Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005737 cytoplasm	IBA GO_REF:0000033	ACCEPT	Summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722]. Reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
GO:0005829 cytosol	IBA GO_REF:0000033	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005955 calcineurin complex	IBA GO_REF:0000033	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0033192 calmodulin-dependent protein phosphatase activity	IBA GO_REF:0000033	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA. Supporting Evidence: file:human/PPP3CA/PPP3CA-deep-research-falcon.md model: Edison Scientific Literature
GO:0005516 calmodulin binding	IBA GO_REF:0000033	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0033173 calcineurin-NFAT signaling cascade	IBA GO_REF:0000033	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0004722 protein serine/threonine phosphatase activity	IEA GO_REF:0000120	ACCEPT	Summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414]. Reason: This is a core molecular-function annotation directly matching the known enzyme class.
GO:0005737 cytoplasm	IEA GO_REF:0000044	ACCEPT	Summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722]. Reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
GO:0005886 plasma membrane	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722]. Reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
GO:0016787 hydrolase activity	IEA GO_REF:0000002	MODIFY	Summary: Hydrolase activity is correct but overly broad for PPP3CA. Reason: A more specific phosphatase term better represents known catalytic chemistry for calcineurin A alpha. Proposed replacements: protein serine/threonine phosphatase activity calmodulin-dependent protein phosphatase activity
GO:0030018 Z disc	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: Z-disc association is described in muscle-context interaction studies [PMID:11114196, PMID:11842093]. Reason: Contextual localization in muscle; not a universal core location.
GO:0033173 calcineurin-NFAT signaling cascade	IEA GO_REF:0000117	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0033192 calmodulin-dependent protein phosphatase activity	IEA GO_REF:0000120	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0042383 sarcolemma	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: Sarcolemma localization is supported in muscle-related contexts [PMID:15955804]. Reason: Context-specific localization; not the most general core compartment term.
GO:0043197 dendritic spine	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: Dendritic-spine localization is plausible in neuronal signaling contexts [PMID:22343722]. Reason: Supported in specific cellular contexts but not a universal core localization.
GO:0097720 calcineurin-mediated signaling	IEA GO_REF:0000002	ACCEPT	Summary: Calcineurin-mediated signaling is a direct and central biological-process role of PPP3CA. Reason: This is a core pathway-level annotation aligned with extensive calcineurin literature.
GO:0005515 protein binding	IPI PMID:12577067 A proteomics strategy to elucidate functional protein-protei...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:16189514 Towards a proteome-scale map of the human protein-protein in...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:17474147 Systematic identification of SH3 domain-mediated human prote...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:19896943 WITHDRAWN: USP14 stabilizes calcineurin and regulates NFAT/A...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:21900206 A directed protein interaction network for investigating int...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:24418105 Direct association of the unique C-terminal tail of transmem...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:25416956 A proteome-scale map of the human interactome network.	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:32814053 Interactome Mapping Provides a Network of Neurodegenerative ...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:37398436 AI-guided pipeline for protein-protein interaction drug disc...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:8524402 Crystal structures of human calcineurin and the human FKBP12...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005829 cytosol	NAS PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	NAS PMID:28126489 The protein serine/threonine phosphatases PP2A, PP1 and calc...	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0070886 positive regulation of calcineurin-NFAT signaling cascade	NAS PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	ACCEPT	Summary: PPP3CA activity supports NFAT activation and therefore positive regulation of calcineurin-NFAT signaling [PMID:22343722, PMID:8631904]. Reason: Term is consistent with known pathway directionality for calcineurin catalytic function.
GO:0070886 positive regulation of calcineurin-NFAT signaling cascade	NAS PMID:8631904 Calcineurin binds the transcription factor NFAT1 and reversi...	ACCEPT	Summary: PPP3CA activity supports NFAT activation and therefore positive regulation of calcineurin-NFAT signaling [PMID:22343722, PMID:8631904]. Reason: Term is consistent with known pathway directionality for calcineurin catalytic function.
GO:1905665 positive regulation of calcium ion import across plasma membrane	NAS PMID:17640527 AKAP79/150 anchoring of calcineurin controls neuronal L-type...	MARK AS OVER ANNOTATED	Summary: Directional regulation of calcium import is highly context-dependent and potentially conflicting across systems. Reason: Process-level directionality is not robust as a core PPP3CA annotation.
GO:1905949 negative regulation of calcium ion import across plasma membrane	NAS PMID:17640527 AKAP79/150 anchoring of calcineurin controls neuronal L-type...	MARK AS OVER ANNOTATED	Summary: Directional regulation of calcium import is highly context-dependent and potentially conflicting across systems. Reason: Process-level directionality is not robust as a core PPP3CA annotation.
GO:0004722 protein serine/threonine phosphatase activity	IMP PMID:30611118 Mitogenic Signals Stimulate the CREB Coactivator CRTC3 throu...	ACCEPT	Summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414]. Reason: This is a core molecular-function annotation directly matching the known enzyme class.
GO:0005829 cytosol	IDA GO_REF:0000052	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:1903235 positive regulation of calcium ion-dependent exocytosis of neurotransmitter	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Neuronal exocytosis-regulation linkage is plausible in synaptic calcineurin signaling. Reason: Likely context-dependent downstream physiology rather than universally core.
GO:0033192 calmodulin-dependent protein phosphatase activity	IDA PMID:30718414 Calcineurin dephosphorylates Kelch-like 3, reversing phospho...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0110062 negative regulation of angiotensin-activated signaling pathway	IDA PMID:30718414 Calcineurin dephosphorylates Kelch-like 3, reversing phospho...	KEEP AS NON CORE	Summary: Supported kidney signaling context where calcineurin opposes angiotensin-driven phosphorylation events [PMID:30718414]. Reason: Evidence is strong but process scope is context-specific rather than core pan-context function.
GO:0004722 protein serine/threonine phosphatase activity	IDA PMID:30718414 Calcineurin dephosphorylates Kelch-like 3, reversing phospho...	ACCEPT	Summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414]. Reason: This is a core molecular-function annotation directly matching the known enzyme class.
GO:0005516 calmodulin binding	EXP PMID:18384083 The complex structure of calmodulin bound to a calcineurin p...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005516 calmodulin binding	IDA PMID:18384083 The complex structure of calmodulin bound to a calcineurin p...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005516 calmodulin binding	IPI PMID:18384083 The complex structure of calmodulin bound to a calcineurin p...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005516 calmodulin binding	EXP PMID:24191726 The distal helix in the regulatory domain of calcineurin is ...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005516 calmodulin binding	IPI PMID:24191726 The distal helix in the regulatory domain of calcineurin is ...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005516 calmodulin binding	EXP PMID:27187005 Calcineurin in a Crowded World.	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005515 protein binding	IPI PMID:34446558 SPATA33 localizes calcineurin to the mitochondria and regula...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0042104 positive regulation of activated T cell proliferation	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Calcineurin signaling contributes to activated T-cell proliferation, but this is a higher-level physiological context. Reason: Biologically plausible yet not the most direct core process label for PPP3CA.
GO:0023057 negative regulation of signaling	ISS GO_REF:0000024	MARK AS OVER ANNOTATED	Summary: Negative regulation of signaling is too broad as a standalone process attribution for PPP3CA. Reason: PPP3CA can both positively and negatively affect distinct pathways depending on substrate/context.
GO:0050804 modulation of chemical synaptic transmission	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Chemical synaptic transmission modulation is plausible in neuronal calcineurin signaling contexts. Reason: Kept as non-core because it is a broad downstream neurophysiology term.
GO:0008544 epidermis development	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Epidermis-development links are mostly orthology/context-derived and represent peripheral biology for PPP3CA. Reason: Retained as non-core because evidence is not the strongest direct core-function signal for human PPP3CA.
GO:0030216 keratinocyte differentiation	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Keratinocyte differentiation linkage is plausible but peripheral relative to core calcineurin signaling. Reason: Evidence is largely contextual/orthology-backed rather than primary core-function evidence.
GO:0005515 protein binding	IPI PMID:28881575 Overexpression of C16orf74 is involved in aggressive pancrea...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005886 plasma membrane	IDA PMID:28881575 Overexpression of C16orf74 is involved in aggressive pancrea...	KEEP AS NON CORE	Summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722]. Reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
GO:0097205 renal filtration	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Renal filtration linkage is consistent with kidney-context calcineurin roles. Reason: Kept as non-core because this is tissue-physiology-level rather than direct molecular process annotation.
GO:0046878 positive regulation of saliva secretion	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Saliva-secretion annotation represents specialized tissue physiology rather than core function. Reason: Retained as non-core due restricted physiological context.
GO:0061006 regulation of cell proliferation involved in kidney morphogenesis	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Kidney morphogenesis/cell proliferation links are plausible but represent specific developmental context. Reason: Retained as non-core due context specificity and indirectness.
GO:0090193 positive regulation of glomerulus development	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Positive regulation of glomerulus development is plausible from renal calcineurin biology. Reason: Non-core developmental physiology term for PPP3CA.
GO:0048741 skeletal muscle fiber development	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Skeletal-muscle-fiber development effects are plausible but peripheral to core enzymatic function. Reason: Represents context-dependent developmental biology rather than central molecular role.
GO:0045672 positive regulation of osteoclast differentiation	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Osteoclast differentiation via calcineurin-NFAT is plausible but context-specific. Reason: Not core across all major PPP3CA biological contexts.
GO:0045669 positive regulation of osteoblast differentiation	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: Osteoblast-differentiation effects are plausible calcineurin/NFAT downstream physiology. Reason: Kept as non-core due indirect/process-level specificity.
GO:0033192 calmodulin-dependent protein phosphatase activity	IMP PMID:30254215 Novel calcineurin A (PPP3CA) variant associated with epileps...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0033173 calcineurin-NFAT signaling cascade	IMP PMID:26248042 Calcineurin Undergoes a Conformational Switch Evoked via Pep...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0097720 calcineurin-mediated signaling	IMP PMID:11005320 Genetic conservation of the immunophilin-binding domains of ...	ACCEPT	Summary: Calcineurin-mediated signaling is a direct and central biological-process role of PPP3CA. Reason: This is a core pathway-level annotation aligned with extensive calcineurin literature.
GO:0042060 wound healing	TAS PMID:18846255 Calsarcin-2 deficiency increases exercise capacity in mice t...	KEEP AS NON CORE	Summary: Wound-healing links reflect downstream physiological contexts of calcineurin/NFAT signaling. Reason: Not a specific core process assignment for PPP3CA itself.
GO:0005737 cytoplasm	IDA PMID:15955804 The sarcolemmal calcium pump inhibits the calcineurin/nuclea...	ACCEPT	Summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722]. Reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
GO:0005886 plasma membrane	IDA PMID:15955804 The sarcolemmal calcium pump inhibits the calcineurin/nuclea...	KEEP AS NON CORE	Summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722]. Reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
GO:0019897 extrinsic component of plasma membrane	IC PMID:15955804 The sarcolemmal calcium pump inhibits the calcineurin/nuclea...	KEEP AS NON CORE	Summary: Extrinsic plasma-membrane association can occur via scaffolded complexes [PMID:22343722]. Reason: Valid in specific contexts, but not the principal localization state.
GO:0033173 calcineurin-NFAT signaling cascade	IMP PMID:15955804 The sarcolemmal calcium pump inhibits the calcineurin/nuclea...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0051117 ATPase binding	IPI PMID:15955804 The sarcolemmal calcium pump inhibits the calcineurin/nuclea...	KEEP AS NON CORE	Summary: ATPase binding is plausible from interaction studies but secondary to phosphatase catalytic function. Reason: Valid interaction-level annotation with limited functional specificity.
GO:0005515 protein binding	IPI PMID:30611118 Mitogenic Signals Stimulate the CREB Coactivator CRTC3 throu...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0043403 skeletal muscle tissue regeneration	TAS PMID:18846255 Calsarcin-2 deficiency increases exercise capacity in mice t...	KEEP AS NON CORE	Summary: Skeletal-muscle regeneration links are plausible but reflect specialized physiological settings. Reason: Not a primary core process for broad PPP3CA function assignment.
GO:0045785 positive regulation of cell adhesion	IMP PMID:21785830 The effect of down regulation of calcineurin Aα by lentivira...	MARK AS OVER ANNOTATED	Summary: Positive regulation of cell adhesion appears mainly from disease/cell-line contexts. Reason: Likely over-extended from context-specific phenotypes rather than core PPP3CA role.
GO:0030335 positive regulation of cell migration	IMP PMID:21785830 The effect of down regulation of calcineurin Aα by lentivira...	MARK AS OVER ANNOTATED	Summary: Positive regulation of cell migration is supported mainly by cancer-context perturbation studies [PMID:20422345, PMID:21785830]. Reason: Likely context-specific/pleiotropic and not a robust core function term for PPP3CA.
GO:0030335 positive regulation of cell migration	IMP PMID:20422345 Calcineurin promotes proliferation, migration, and invasion ...	MARK AS OVER ANNOTATED	Summary: Positive regulation of cell migration is supported mainly by cancer-context perturbation studies [PMID:20422345, PMID:21785830]. Reason: Likely context-specific/pleiotropic and not a robust core function term for PPP3CA.
GO:0005515 protein binding	IPI PMID:18218901 NFAT binding and regulation of T cell activation by the cyto...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:12809556 Phosphorylation of calcipressin 1 increases its ability to i...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:12218175 Crystal structure of calcineurin-cyclophilin-cyclosporin sho...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:26248042 Calcineurin Undergoes a Conformational Switch Evoked via Pep...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:27974827 Investigating the human Calcineurin Interaction Network usin...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005516 calmodulin binding	IDA PMID:19404396 Domain swapping and different oligomeric States for the comp...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005737 cytoplasm	IDA PMID:19154138 The proline-rich N-terminal sequence of calcineurin Abeta de...	ACCEPT	Summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722]. Reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
GO:0005737 cytoplasm	IDA PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	ACCEPT	Summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722]. Reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
GO:0005955 calcineurin complex	IDA PMID:12218175 Crystal structure of calcineurin-cyclophilin-cyclosporin sho...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0005955 calcineurin complex	IDA PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0005955 calcineurin complex	IDA PMID:23468591 The molecular mechanism of substrate engagement and immunosu...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0005955 calcineurin complex	IDA PMID:27974827 Investigating the human Calcineurin Interaction Network usin...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0006470 protein dephosphorylation	IDA PMID:19154138 The proline-rich N-terminal sequence of calcineurin Abeta de...	ACCEPT	Summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414]. Reason: This accurately reflects catalytic activity on phosphoprotein substrates.
GO:0009898 cytoplasmic side of plasma membrane	IDA PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	KEEP AS NON CORE	Summary: PPP3CA can localize on the cytoplasmic side of membrane-associated signaling complexes [PMID:22343722]. Reason: Supported by scaffolded signaling, but context-specific.
GO:0033173 calcineurin-NFAT signaling cascade	IDA PMID:19154138 The proline-rich N-terminal sequence of calcineurin Abeta de...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0033173 calcineurin-NFAT signaling cascade	IMP PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0033173 calcineurin-NFAT signaling cascade	IMP PMID:23468591 The molecular mechanism of substrate engagement and immunosu...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0033192 calmodulin-dependent protein phosphatase activity	IDA PMID:19154138 The proline-rich N-terminal sequence of calcineurin Abeta de...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0033192 calmodulin-dependent protein phosphatase activity	IDA PMID:23468591 The molecular mechanism of substrate engagement and immunosu...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0043197 dendritic spine	IDA PMID:22343722 Balanced interactions of calcineurin with AKAP79 regulate Ca...	KEEP AS NON CORE	Summary: Dendritic-spine localization is plausible in neuronal signaling contexts [PMID:22343722]. Reason: Supported in specific cellular contexts but not a universal core localization.
GO:0005515 protein binding	IPI PMID:12357034 Crystal structure of human calcineurin complexed with cyclos...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005955 calcineurin complex	IDA PMID:12357034 Crystal structure of human calcineurin complexed with cyclos...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0005515 protein binding	IPI PMID:22688515 Na(+)/H(+) exchanger 1 directly binds to calcineurin A and a...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005955 calcineurin complex	IDA PMID:22688515 Na(+)/H(+) exchanger 1 directly binds to calcineurin A and a...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.
GO:0033173 calcineurin-NFAT signaling cascade	IDA PMID:22688515 Na(+)/H(+) exchanger 1 directly binds to calcineurin A and a...	ACCEPT	Summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904]. Reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
GO:0045944 positive regulation of transcription by RNA polymerase II	IDA PMID:22688515 Na(+)/H(+) exchanger 1 directly binds to calcineurin A and a...	KEEP AS NON CORE	Summary: PPP3CA can promote transcription indirectly through NFAT dephosphorylation and nuclear translocation [PMID:22688515]. Reason: Downstream regulatory consequence, not direct transcription-factor molecular function.
GO:0005829 cytosol	TAS Reactome:R-HSA-2025890	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	TAS Reactome:R-HSA-2730849	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	TAS Reactome:R-HSA-2730867	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	TAS Reactome:R-HSA-2730872	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	TAS Reactome:R-HSA-4551451	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005829 cytosol	TAS Reactome:R-HSA-4551465	ACCEPT	Summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722]. Reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
GO:0005654 nucleoplasm	TAS Reactome:R-HSA-2730867	KEEP AS NON CORE	Summary: Nucleoplasmic context can occur during NFAT-related signaling translocation events (Reactome evidence). Reason: Reasonable pathway-context localization, but less central than cytosolic/calcineurin-complex roles.
GO:0005654 nucleoplasm	TAS Reactome:R-HSA-4551465	KEEP AS NON CORE	Summary: Nucleoplasmic context can occur during NFAT-related signaling translocation events (Reactome evidence). Reason: Reasonable pathway-context localization, but less central than cytosolic/calcineurin-complex roles.
GO:0006470 protein dephosphorylation	IDA PMID:18815128 CHP2 activates the calcineurin/nuclear factor of activated T...	ACCEPT	Summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414]. Reason: This accurately reflects catalytic activity on phosphoprotein substrates.
GO:0033192 calmodulin-dependent protein phosphatase activity	IDA PMID:18815128 CHP2 activates the calcineurin/nuclear factor of activated T...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0051592 response to calcium ion	IDA PMID:18815128 CHP2 activates the calcineurin/nuclear factor of activated T...	ACCEPT	Summary: PPP3CA is activated by intracellular calcium signaling and participates in calcium-responsive pathways. Reason: This broad process term is directionally consistent with calcineurin biology.
GO:0005516 calmodulin binding	IDA PMID:11005320 Genetic conservation of the immunophilin-binding domains of ...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0019899 enzyme binding	IDA PMID:11005320 Genetic conservation of the immunophilin-binding domains of ...	KEEP AS NON CORE	Summary: PPP3CA binds multiple enzyme partners/regulators, but this term is broad and secondary to catalytic function. Reason: Retained as non-core due limited specificity.
GO:0042110 T cell activation	TAS PMID:11005320 Genetic conservation of the immunophilin-binding domains of ...	KEEP AS NON CORE	Summary: T-cell activation involvement is compatible with canonical calcineurin-immunology biology. Reason: Retained as non-core due pathway-level context and isoform/redundancy considerations.
GO:0046983 protein dimerization activity	IPI PMID:11005320 Genetic conservation of the immunophilin-binding domains of ...	REMOVE	Summary: Protein dimerization activity is not a well-supported or informative core MF for PPP3CA. Reason: Evidence better supports regulated complex assembly (calcineurin holoenzyme) rather than standalone dimerization activity.
GO:0016311 dephosphorylation	TAS PMID:2556704 Cloning of human calcineurin A: evidence for two isozymes an...	ACCEPT	Summary: Dephosphorylation is the defining catalytic process of PPP3CA/calcineurin. Reason: Accurately reflects direct enzyme activity.
GO:0033192 calmodulin-dependent protein phosphatase activity	TAS PMID:2556704 Cloning of human calcineurin A: evidence for two isozymes an...	ACCEPT	Summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591]. Reason: This term captures the specific enzymatic mechanism of PPP3CA.
GO:0005515 protein binding	IPI PMID:18838687 Dephosphorylation by calcineurin regulates translocation of ...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:11114196 Calsarcins, a novel family of sarcomeric calcineurin-binding...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0005515 protein binding	IPI PMID:11842093 Calsarcin-3, a novel skeletal muscle-specific member of the ...	REMOVE	Summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA. Reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
GO:0006470 protein dephosphorylation	NAS PMID:8392375 Molecular cloning of a full-length cDNA encoding the catalyt...	ACCEPT	Summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414]. Reason: This accurately reflects catalytic activity on phosphoprotein substrates.
GO:0004722 protein serine/threonine phosphatase activity	NAS PMID:8392375 Molecular cloning of a full-length cDNA encoding the catalyt...	ACCEPT	Summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414]. Reason: This is a core molecular-function annotation directly matching the known enzyme class.
GO:0005509 calcium ion binding	NAS PMID:8392375 Molecular cloning of a full-length cDNA encoding the catalyt...	MARK AS OVER ANNOTATED	Summary: Direct calcium-ion binding by PPP3CA catalytic subunit is less specific than calmodulin-dependent activation and holoenzyme regulation. Reason: Annotation is plausible at a broad level but overstates direct, independently informative MF for PPP3CA.
GO:0005516 calmodulin binding	NAS PMID:8392375 Molecular cloning of a full-length cDNA encoding the catalyt...	ACCEPT	Summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396]. Reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
GO:0005955 calcineurin complex	NAS PMID:8392375 Molecular cloning of a full-length cDNA encoding the catalyt...	ACCEPT	Summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591]. Reason: Complex membership is definitive and foundational to PPP3CA biology.

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000024

Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000052

Gene Ontology annotation based on curation of immunofluorescence data

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:11005320

Genetic conservation of the immunophilin-binding domains of human calcineurin A1 and A2.

PMID:11114196

Calsarcins, a novel family of sarcomeric calcineurin-binding proteins.

PMID:11842093

Calsarcin-3, a novel skeletal muscle-specific member of the calsarcin family, interacts with multiple Z-disc proteins.

PMID:12218175

Crystal structure of calcineurin-cyclophilin-cyclosporin shows common but distinct recognition of immunophilin-drug complexes.

PMID:12357034

Crystal structure of human calcineurin complexed with cyclosporin A and human cyclophilin.

PMID:12577067

A proteomics strategy to elucidate functional protein-protein interactions applied to EGF signaling.

PMID:12809556

Phosphorylation of calcipressin 1 increases its ability to inhibit calcineurin and decreases calcipressin half-life.

PMID:15955804

The sarcolemmal calcium pump inhibits the calcineurin/nuclear factor of activated T-cell pathway via interaction with the calcineurin A catalytic subunit.

PMID:16189514

Towards a proteome-scale map of the human protein-protein interaction network.

PMID:17474147

Systematic identification of SH3 domain-mediated human protein-protein interactions by peptide array target screening.

PMID:17640527

AKAP79/150 anchoring of calcineurin controls neuronal L-type Ca2+ channel activity and nuclear signaling.

PMID:18218901

NFAT binding and regulation of T cell activation by the cytoplasmic scaffolding Homer proteins.

PMID:18384083

The complex structure of calmodulin bound to a calcineurin peptide.

PMID:18815128

CHP2 activates the calcineurin/nuclear factor of activated T cells signaling pathway and enhances the oncogenic potential of HEK293 cells.

PMID:18838687

Dephosphorylation by calcineurin regulates translocation of Drp1 to mitochondria.

PMID:18846255

Calsarcin-2 deficiency increases exercise capacity in mice through calcineurin/NFAT activation.

PMID:19154138

The proline-rich N-terminal sequence of calcineurin Abeta determines substrate binding.

PMID:19404396

Domain swapping and different oligomeric States for the complex between calmodulin and the calmodulin-binding domain of calcineurin a.

PMID:19896943

WITHDRAWN: USP14 stabilizes calcineurin and regulates NFAT/AP-1 dependent IL-4 transcription as a novel calcineurin-binding protein.

PMID:20422345

Calcineurin promotes proliferation, migration, and invasion of small cell lung cancer.

PMID:21785830

The effect of down regulation of calcineurin Aα by lentiviral vector-mediated RNAi on the biological behavior of small-cell lung cancer and its bone metastasis.

PMID:21900206

A directed protein interaction network for investigating intracellular signal transduction.

PMID:22343722

Balanced interactions of calcineurin with AKAP79 regulate Ca2+-calcineurin-NFAT signaling.

PMID:22688515

Na(+)/H(+) exchanger 1 directly binds to calcineurin A and activates downstream NFAT signaling, leading to cardiomyocyte hypertrophy.

PMID:23468591

The molecular mechanism of substrate engagement and immunosuppressant inhibition of calcineurin.

PMID:24191726

The distal helix in the regulatory domain of calcineurin is important for domain stability and enzyme function.

PMID:24418105

Direct association of the unique C-terminal tail of transmembrane AMPA receptor regulatory protein γ-8 with calcineurin.

PMID:25416956

A proteome-scale map of the human interactome network.

PMID:2556704

Cloning of human calcineurin A: evidence for two isozymes and identification of a polyproline structural domain.

PMID:26248042

Calcineurin Undergoes a Conformational Switch Evoked via Peptidyl-Prolyl Isomerization.

PMID:27187005

Calcineurin in a Crowded World.

PMID:27974827

Investigating the human Calcineurin Interaction Network using the πɸLxVP SLiM.

PMID:28126489

The protein serine/threonine phosphatases PP2A, PP1 and calcineurin: A triple threat in the regulation of the neuronal cytoskeleton.

PMID:28881575

Overexpression of C16orf74 is involved in aggressive pancreatic cancers.

PMID:30254215

Novel calcineurin A (PPP3CA) variant associated with epilepsy, constitutive enzyme activation and downregulation of protein expression.

PMID:30611118

Mitogenic Signals Stimulate the CREB Coactivator CRTC3 through PP2A Recruitment.

PMID:30718414

Calcineurin dephosphorylates Kelch-like 3, reversing phosphorylation by angiotensin II and regulating renal electrolyte handling.

PMID:32814053

Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.

PMID:33961781

Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.

PMID:34446558

SPATA33 localizes calcineurin to the mitochondria and regulates sperm motility in mice.

PMID:37398436

AI-guided pipeline for protein-protein interaction drug discovery identifies a SARS-CoV-2 inhibitor.

PMID:8392375

Molecular cloning of a full-length cDNA encoding the catalytic subunit of human calmodulin-dependent protein phosphatase (calcineurin A alpha).

PMID:8524402

Crystal structures of human calcineurin and the human FKBP12-FK506-calcineurin complex.

PMID:8631904

Calcineurin binds the transcription factor NFAT1 and reversibly regulates its activity.

Reactome:R-HSA-2025890

Calcineurin binds NFATC1,2,3

Reactome:R-HSA-2730849

Calcineurin binds and dephosphorylates NFAT

Reactome:R-HSA-2730867

Translocation of CaN:CaM:NFAT to nucleus

Reactome:R-HSA-2730872

Activation of Calcineurin

Reactome:R-HSA-4551451

Calcineurin binds and dephosphorylates NFAT1 in response to WNT/Ca2+ signaling

Reactome:R-HSA-4551465

Translocation of NFATC1:CaN:CaM to nucleus

file:human/PPP3CA/PPP3CA-deep-research-falcon.md

Deep research report on PPP3CA

Deep Research

Falcon

(PPP3CA-deep-research-falcon.md)

Research Report: Human **PPP3CA** (UniProt **Q08209**) — Functional Annotation of Calcineurin Aα (PP2B catalytic subunit) Falcon Edison Scientific Literature 36 citations 2026-03-07T13:33:59.592457

Research Report: Human PPP3CA (UniProt Q08209) — Functional Annotation of Calcineurin Aα (PP2B catalytic subunit)

1. Target verification and gene/protein identity

PPP3CA (human) encodes calcineurin catalytic subunit A alpha (CnAα), the catalytic subunit of calcineurin (also termed PP2B/PPP3), a Ca2+/calmodulin-regulated serine/threonine phosphatase that functions as a heterodimer with the regulatory calcineurin B (CnB) subunit. This identity is explicitly supported by a 2024 PPP3CA genetics/functional paper that maps PPP3CA to UniProt Q08209 and by recent mechanistic reviews describing calcineurin A/B composition and regulation. (castiglioni2024expandingtheclinical pages 1-3, lim2023calcineurinsignallingin pages 2-4)

2. Key concepts and current mechanistic understanding

2.1. Enzymatic function (reaction class and specificity)

Calcineurin is a Ca2+/calmodulin-dependent Ser/Thr protein phosphatase that removes phosphate from serine/threonine residues of protein substrates, thereby regulating substrate activity, stability, and localization across multiple pathways. (lim2023calcineurinsignallingin pages 2-4, nolze2023calcineurinisa pages 3-4)

A core modern concept in calcineurin substrate selection is that many substrates are recruited by short linear motifs (SLiMs) that dock onto defined pockets on the calcineurin holoenzyme. Two major docking systems are:
- PxIxIT motif binding a pocket on CnA (PPP3CA) (lim2023calcineurinsignallingin pages 2-4)
- LxVP motif binding a pocket at the CnA–CnB interface, which becomes properly formed/accessible with CnB participation and Ca2+-dependent activation (lim2023calcineurinsignallingin pages 2-4)

A 2024 review further emphasizes that these docking motifs are central determinants of substrate/regulator engagement and also notes that calcineurin activity requires Zn2+ and Fe2+ as catalytic cofactors. (fonodi2024roleofprotein pages 15-16)

2.2. Holoenzyme architecture, domains, and activation by Ca2+/calmodulin

Calcineurin comprises a catalytic A subunit (~60 kDa) and a regulatory B subunit (~19 kDa). CnA contains an N-terminal catalytic domain, a CnB-binding region, and a C-terminal regulatory tail that includes a calmodulin-binding domain (CaMBD) and an autoinhibitory domain (AID). (lim2023calcineurinsignallingin pages 2-4)

Activation mechanism (current model):
- At low Ca2+, the AID suppresses enzymatic function.
- Rising intracellular Ca2+ binds CnB EF-hands and also binds calmodulin; Ca2+/calmodulin binding to CnA helps displace autoinhibition and enables substrate engagement. (lim2023calcineurinsignallingin pages 2-4, nolze2023calcineurinisa pages 3-4)
- Quantitatively, for purified CnB, Ca2+ binding has been reported in the nanomolar range (Kd ~30–150 nM) for high-affinity sites, supporting CnB’s role as an intracellular Ca2+ sensor. (lim2023calcineurinsignallingin pages 2-4)

Docking-pocket logic: Two substrate-interaction pockets are highlighted in recent mechanistic synthesis: the PxIxIT pocket (on CnA) and the LxVP pocket (at the CnA–CnB interface). Loss of CnB disrupts the LxVP pocket and inactivates the enzyme. (lim2023calcineurinsignallingin pages 2-4)

2.3. PPP3CA isoforms (human) and domain layout (UniProt Q08209)

A 2024 Orphanet Journal of Rare Diseases study provides a gene-centric isoform and domain overview for PPP3CA/Q08209:
- Isoform 1 (Q08209-1, canonical): 521 aa
- Isoform 2: 511 aa
- Isoform 3: 469 aa
- Isoform 4: 289 aa
- Isoform 5: 454 aa
and describes the major architectural regions: catalytic domain, CnB-binding site, and a regulatory region containing CaM binding and autoinhibitory segments/domains. (castiglioni2024expandingtheclinical pages 1-3)

A cropped figure from this 2024 paper depicts the domain architecture for the canonical isoform and the positions of the regulatory elements. (castiglioni2024expandingtheclinical media 7cdbd3c3)

3. Pathways, biological processes, and cellular context

3.1. Canonical Ca2+–calcineurin–NFAT signaling

The most widely characterized calcineurin pathway is NFAT (nuclear factor of activated T cells) activation: calcineurin dephosphorylates NFAT family transcription factors, enabling NFAT nuclear translocation and transcriptional activity. (masaki2023calcineurinmediateddephosphorylationenhances pages 1-2, nolze2023calcineurinisa pages 3-4)

In immune contexts, calcineurin–NFAT signaling is described as a master regulator in T cells, controlling cytokine gene expression including IL-2, IL-17, and TNFα. (nolze2023calcineurinisa pages 4-5)

Selectivity strategies: a peptide inhibitor concept highlighted in a 2023 vascular review is VIVIT, which selectively disrupts calcineurin–NFAT interaction by mimicking NFAT docking features, conceptually separating NFAT-specific signaling from broader calcineurin substrates. (nolze2023calcineurinisa pages 3-4)

3.2. CNS/astrocyte signaling: calcineurin as a Ca2+-sensitive switch

A 2023 Neurochemical Research review positions calcineurin as a Ca2+-sensitive molecular switch in astrocytes, linking Ca2+ dynamics to astrocytic functional states and downstream effects on neuronal function. It also emphasizes that mammalian calcineurin A has multiple isoforms (α/β/γ) and that CnB1 is a CNS-expressed regulatory isoform. (lim2023calcineurinsignallingin pages 2-4)

3.3. Vascular smooth muscle and cardiovascular biology

A 2023 Cells review focusing on vascular smooth muscle cells (VSMCs) frames calcineurin as a broad regulator of vessel function, acting through transcription factors (including NFAT, CREB, FOXO, MEF2, TFEB) and through dephosphorylation/regulation of ion-handling proteins and channels (e.g., AMPA/NMDA receptors, ryanodine receptors, NCX1, L-type Ca2+ channels). (nolze2023calcineurinisa pages 3-4)

3.4. Kidney biology and clinical renal contexts

The same 2023 vascular review links calcineurin/NFAT signaling to renal pathophysiology and clinical nephrology contexts, including calcineurin inhibitor nephrotoxicity, hypertrophy-related processes, and renal fibrosis/extracellular matrix accumulation, while also highlighting voclosporin as a clinical calcineurin inhibitor used in lupus nephritis. (nolze2023calcineurinisa pages 4-5, nolze2023calcineurinisa pages 16-18)

4. Substrates and functional outputs (selected examples with experimental support)

4.1. c-Myc stability via direct dephosphorylation (primary evidence, 2023)

A 2023 primary study reports that calcineurin directly dephosphorylates c-Myc at Thr58 and Ser62, thereby reducing recognition by the ubiquitin ligase Fbxw7 and stabilizing c-Myc. In a mouse xenograft setting, calcineurin inhibition by FK506 decreased c-Myc expression and increased phosphorylation at Thr58/Ser62. (masaki2023calcineurinmediateddephosphorylationenhances pages 1-2)

4.2. TFEB and autophagy/lysosomal biogenesis (pathway placement)

A 2023 vascular review summarizes that calcineurin can dephosphorylate transcription factors including TFEB, connecting Ca2+/calcineurin signaling to transcriptional programs involved in lysosomal/autophagy regulation. (nolze2023calcineurinisa pages 3-4)

4.3. Synaptic receptors and Ca2+ handling proteins (systems-level role)

Calcineurin is described as targeting multiple membrane proteins and ion channels in neuronal and smooth muscle contexts (AMPA/NMDA receptors; ryanodine receptors; NCX1; L-type Ca2+ channels), consistent with roles in synaptic plasticity and Ca2+ homeostasis. (nolze2023calcineurinisa pages 3-4)

5. Recent developments (prioritizing 2023–2024)

5.1. 2024: PPP3CA variants and isoform-specific disease mechanisms

A 2024 study expanded the clinical spectrum of PPP3CA-related disorders and highlighted that alternative isoforms matter. It reports two new de novo PPP3CA variants (a frameshift predicted to truncate protein; and a splice-site variant associated with a milder phenotype) and integrates these with earlier genotype–phenotype patterns (e.g., catalytic-domain loss-of-function vs autoinhibitory-domain gain-of-function). (castiglioni2024expandingtheclinical pages 1-3)

Quantitative variant and cohort information: the study notes 23 pathogenic variants known in its abstract and elsewhere states 24 pathogenic variants described in 29 patients. (castiglioni2024expandingtheclinical pages 1-3)

Isoform expression (quantitative): the same work reports patient-specific isoform imbalance at the transcript level, e.g., in Patient 1, isoform 1 decreased to 0.3-fold vs controls and isoform 2 increased 2.8-fold; Patient 2 showed 0.7-fold isoform 2 expression. (castiglioni2024expandingtheclinical pages 4-5)

Cellular phenotypes and ER stress: Patient-derived lymphoblastoid cell lines showed reduced proliferation, increased cell death, and UPR activation with reported marker changes (e.g., BiP ~2.3-fold, CHOP ~4.5-fold, XBP1 ~2.3-fold in Patient 1; partial activation in Patient 2). (castiglioni2024expandingtheclinical pages 5-7)

5.2. 2024: Calcineurin–NFAT signaling in human neutrophils and antifungal immunity

A 2024 primary study tested human neutrophils challenged with Candida albicans and Aspergillus fumigatus and showed that NFAT pathway members are expressed in neutrophils and that pathogen exposure upregulated chemokines CCL2, CCL3, and CCL4. Importantly, clinically used CN–NFAT inhibitors attenuated chemokine expression and impaired neutrophil-mediated chemoattraction, providing a direct mechanistic link between calcineurin inhibition and susceptibility to opportunistic fungal infections in immunosuppressed settings. (vymazal2024calcineurinnfatsignalingcontrols pages 1-2)

5.3. 2023–2024: Emerging mechanistic framing and therapeutic caveats

A 2024 review focusing on phosphatases in angiogenesis reinforces motif-based docking (PxIxIT/LxVP) and notes that CsA/FK506 bind the LxVP pocket, but it also highlights complex outcomes including reports of paradoxical pro-angiogenic effects and calcineurin-independent mitochondrial ROS effects with cyclosporine in endothelial cells, underscoring why broad calcineurin inhibition can have context-dependent biology. (fonodi2024roleofprotein pages 15-16)

6. Current applications and real-world implementations

6.1. Calcineurin inhibitors (CNIs) as immunosuppressants and targeted anti-inflammatory agents

A 2023 vascular review lists widely used CNIs—cyclosporine A, tacrolimus (FK506), pimecrolimus, voclosporine—and summarizes their mechanism: drug–immunophilin complexes competitively inhibit calcineurin and block NFAT dephosphorylation, forming the mechanistic basis for immunosuppression and anti-inflammatory efficacy. (nolze2023calcineurinisa pages 3-4)

6.2. Lupus nephritis: voclosporin outcomes and comparative evidence

A 2025 review (covering literature through 2024) reports that voclosporin achieved higher renal response at 52 weeks (40.8% vs 22.5%) compared with standard therapy, and emphasizes stable pharmacokinetics that may reduce monitoring burden. (ashinze2025voclosporinacomprehensive pages 1-2)

A 2026 network meta-analysis synthesizing 16 randomized trials (n = 1,994) ranks voclosporin-based triple therapy highest for remission (SUCRA 84.3%), followed by tacrolimus-based triple therapy (SUCRA 78.0%), and flags infection risk signals (voclosporin infection SUCRA 20.6%; tacrolimus 27.0%). (wu2026efficacyandsafety pages 1-2)

6.3. Clinical trial registry implementations (transplantation and beyond)

Registry evidence shows long-standing clinical translation of calcineurin pathway modulation:
- NCT00270634 (PROMISE): voclosporin vs tacrolimus in de novo renal transplantation, Phase IIb, n=334, endpoint biopsy-proven acute rejection at 6 months. (NCT00270634 chunk 1)
- NCT01429844: tacrolimus vs cyclosporine after lung transplantation, Phase 3, n=274, endpoint bronchiolitis obliterans syndrome over 3 years, with trough targets specified. (NCT01429844 chunk 1)
- NCT00038948: conversion to sirolimus vs continued calcineurin inhibitors in kidney transplant recipients, Phase 3, n=830, endpoint 52-week GFR. (NCT00038948 chunk 1)

7. Expert synthesis and interpretation (authoritative-source grounded)

7.1. Why calcineurin is hard to “functionally annotate” as a single-target enzyme

Across 2023–2024 sources, calcineurin emerges less as a single-pathway enzyme and more as a Ca2+-responsive integrator whose specificity is strongly shaped by (i) substrate SLiM docking (PxIxIT/LxVP), (ii) activation-state controlled by Ca2+/calmodulin and the AID, and (iii) scaffolding/compartmentalization (e.g., ion channel proximity in excitable cells). This makes PPP3CA best annotated by mechanism (Ca2+-regulated Ser/Thr dephosphorylation) plus recruitment logic (docking motifs) rather than by a narrow substrate list. (lim2023calcineurinsignallingin pages 2-4, fonodi2024roleofprotein pages 15-16, nolze2023calcineurinisa pages 3-4)

7.2. Therapeutic implication: separating “NFAT biology” from “calcineurin biology”

Clinically, most CNI benefits and toxicities come from broad calcineurin inhibition. Modern pathway-targeting concepts therefore focus on selective blockade of calcineurin–NFAT interaction (e.g., VIVIT peptide) to reduce immunosuppression-related adverse effects while preserving other calcineurin functions, though broad clinical translation remains limited. (nolze2023calcineurinisa pages 3-4)

8. Summary tables (for rapid reference)

Aspect	Key points	Best recent sources	Publication date	URL
Identity	Human PPP3CA encodes calcineurin catalytic subunit Aα (PP2B-Aα), a Ca2+/calmodulin-regulated serine/threonine phosphatase that functions as a heterodimer with the regulatory B subunit.	Lim 2023; Castiglioni 2024 (lim2023calcineurinsignallingin pages 2-4, castiglioni2024expandingtheclinical pages 1-3)	Sep 2023; Dec 2024	https://doi.org/10.1007/s11064-022-03744-4; https://doi.org/10.1186/s13023-024-03507-0
Complex/activation	Activation requires Ca2+ binding to CNB EF-hands (Kd ≈ 30–150 nM) and calmodulin binding to the CaMBD, which relieves the autoinhibitory domain; proteolytic removal of the C-terminal tail yields constitutive activity.	Lim 2023 (lim2023calcineurinsignallingin pages 2-4)	Sep 2023	https://doi.org/10.1007/s11064-022-03744-4
Domains/isoforms	Canonical architecture: catalytic domain, CNB-binding region, regulatory domain with CaMBD, autoinhibitory segment/domain; five human isoforms: 521, 511, 469, 289, and 454 aa (isoform 1 predominates in CNS).	Castiglioni 2024; Castiglioni 2024 Fig. 1A (castiglioni2024expandingtheclinical pages 1-3, castiglioni2024expandingtheclinical media 7cdbd3c3)	Dec 2024	https://doi.org/10.1186/s13023-024-03507-0
Docking motifs/cofactors	Substrates use PxIxIT (binds CNA) and LxVP (binds CNA–CNB interface) docking motifs; calcineurin’s catalytic site uses Zn2+ and Fe2+ cofactors.	Fonódi 2024; Lim 2023 (fonodi2024roleofprotein pages 15-16, lim2023calcineurinsignallingin pages 2-4)	Jun 2024; Sep 2023	https://doi.org/10.3390/ijms25136868; https://doi.org/10.1007/s11064-022-03744-4
Example substrates/pathways	NFAT dephosphorylation drives nuclear translocation; calcineurin also regulates TFEB, CREB, FOXO, MEF2, and neuronal channels; PPP3CA directly dephosphorylates c-Myc at Thr58/Ser62 to enhance stability/transactivation.	Nolze 2023; Masaki 2023 (nolze2023calcineurinisa pages 3-4, masaki2023calcineurinmediateddephosphorylationenhances pages 1-2)	Sep 2023; Aug 2023	https://doi.org/10.3390/cells12182269; https://doi.org/10.1038/s41598-023-40412-1
Inhibitors/drugs	Clinically used CNIs: cyclosporine A (cyclophilin complex), tacrolimus/FK506 (FKBP complex), pimecrolimus, and voclosporine; VIVIT peptide selectively blocks calcineurin–NFAT docking.	Nolze 2023 (nolze2023calcineurinisa pages 3-4)	Sep 2023	https://doi.org/10.3390/cells12182269
Disease links	PPP3CA pathogenic variants (≈23–24 reported) cause developmental and epileptic encephalopathy (DEE91); isoform balance can modulate phenotype severity.	Castiglioni 2024 (castiglioni2024expandingtheclinical pages 1-3)	Dec 2024	https://doi.org/10.1186/s13023-024-03507-0
Quantitative stats	CNB Ca2+ Kd ≈ 30–150 nM; PPP3CA variants ≈23–24; voclosporin renal response 52 w: 40.8% vs 22.5% over standard care; network meta-analysis: voclosporin triple SUCRA 84.3% (remission), highest infection risk SUCRA 20.6% (tacrolimus second at 27.0%).	Lim 2023; Castiglioni 2024; Ashinze 2025; Wu 2026 (lim2023calcineurinsignallingin pages 2-4, castiglioni2024expandingtheclinical pages 1-3, ashinze2025voclosporinacomprehensive pages 1-2, wu2026efficacyandsafety pages 1-2)	Sep 2023; Dec 2024; Jun 2025; Jan 2026	https://doi.org/10.1007/s11064-022-03744-4; https://doi.org/10.1186/s13023-024-03507-0; https://doi.org/10.1097/md.0000000000042858; https://doi.org/10.3389/fimmu.2025.1670134
Real‑world applications	CNIs are cornerstone immunosuppressants (transplant, dermatology) and effective in lupus nephritis; voclosporin offers stable PK and favorable efficacy/safety profile relative to traditional CNIs.	Ashinze 2025; Nolze 2023 (ashinze2025voclosporinacomprehensive pages 1-2, nolze2023calcineurinisa pages 3-4)	Jun 2025; Sep 2023	https://doi.org/10.1097/md.0000000000042858; https://doi.org/10.3390/cells12182269

Table: Concise table of PPP3CA (calcineurin Aα) identity, structure, activation, motifs, substrates, inhibitors, disease links, and key quantitative data. Recent authoritative sources and URLs are provided to support each major point.

Intervention/drug	Mechanism (calcineurin inhibition via immunophilin complex; blocks NFAT dephosphorylation)	Indication/setting	Evidence type	Key quantitative data	Publication date	URL
Voclosporin vs tacrolimus (NCT00270634)	CNIs (voclosporin, tacrolimus) bind immunophilins (cyclophilin/FKBP) to inhibit calcineurin, preventing NFAT dephosphorylation and nuclear translocation (nolze2023calcineurinisa pages 3-4)	De novo renal transplantation	Trial registry (Phase IIb) (NCT00270634 chunk 1, NCT00270634 chunk 2)	n=334; primary endpoint: BPAR at 6 months; dosing: voclosporin 0.4/0.6/0.8 mg/kg BID; tacrolimus 0.05 mg/kg BID (NCT00270634 chunk 1)	2006	https://clinicaltrials.gov/study/NCT00270634
Tacrolimus vs cyclosporine (NCT01429844)	Tacrolimus/cyclosporine–immunophilin complexes inhibit calcineurin and NFAT activation (nolze2023calcineurinisa pages 3-4)	Lung transplantation (prevention of bronchiolitis obliterans syndrome)	Trial registry (Phase 3) (NCT01429844 chunk 1)	n=274; primary endpoint: BOS incidence over 3 years; target troughs: tacrolimus 10–15 ng/mL (0–3 mo) then 8–12; cyclosporine 200–300 ng/mL (0–3 mo) then 150–200 (NCT01429844 chunk 1)	2001 (start); 2010 (completion)	https://clinicaltrials.gov/study/NCT01429844
Conversion to sirolimus vs continued CNI (NCT00038948)	Comparator arm continues CNI mechanism (calcineurin–NFAT blockade via immunophilin complex) (nolze2023calcineurinisa pages 3-4)	Kidney transplant recipients (renal function optimization)	Trial registry (Phase 3) (NCT00038948 chunk 1)	n=830; primary endpoint: 52-week GFR (Nankivell); randomized open-label (NCT00038948 chunk 1)	2002 (start); 2008 (completion)	https://clinicaltrials.gov/study/NCT00038948
Voclosporin in lupus nephritis (AURORA program)	Oral CNI inhibits calcineurin–NFAT in T cells; added podocyte-stabilizing effects reported (nolze2023calcineurinisa pages 3-4, ashinze2025voclosporinacomprehensive pages 1-2)	Lupus nephritis (SLE)	Narrative review of clinical trials (ashinze2025voclosporinacomprehensive pages 1-2)	52-week renal response: 40.8% (voclosporin triple) vs 22.5% (standard) (ashinze2025voclosporinacomprehensive pages 1-2)	Jun 2025	https://doi.org/10.1097/md.0000000000042858
CNIs in lupus nephritis (network meta-analysis)	Class effect: calcineurin inhibition blocks NFAT dephosphorylation; regimen-specific differences observed (nolze2023calcineurinisa pages 3-4, wu2026efficacyandsafety pages 1-2)	Lupus nephritis (multiple RCTs)	Systematic review and network meta-analysis (16 RCTs; 1,994 pts) (wu2026efficacyandsafety pages 1-2)	Total remission SUCRA: voclosporin triple 84.3%, tacrolimus triple 78.0%; infection risk SUCRA: voclosporin 20.6% (highest), tacrolimus 27.0% (wu2026efficacyandsafety pages 1-2)	Jan 2026	https://doi.org/10.3389/fimmu.2025.1670134

Table: Clinical and meta-analytic evidence for calcineurin inhibitors (relevant to PPP3CA/calcineurin signaling), summarizing mechanisms, indications, trial phases/enrollments, endpoints, and key outcomes. Citations point to registry records and recent peer-reviewed syntheses for lupus nephritis efficacy and safety.

9. Key source URLs (recent, authoritative)

Castiglioni S. et al. “Expanding the clinical spectrum of PPP3CA variants – alternative isoforms matter.” Orphanet J Rare Dis (Dec 2024). https://doi.org/10.1186/s13023-024-03507-0 (castiglioni2024expandingtheclinical pages 1-3)
Lim D. et al. “Calcineurin signalling in astrocytes…” Neurochemical Research (Sep 2023). https://doi.org/10.1007/s11064-022-03744-4 (lim2023calcineurinsignallingin pages 2-4)
Nolze A. et al. “Calcineurin Is a Universal Regulator of Vessel Function…” Cells (Sep 2023). https://doi.org/10.3390/cells12182269 (nolze2023calcineurinisa pages 3-4)
Masaki T. et al. “Calcineurin-mediated dephosphorylation enhances the stability and transactivation of c-Myc.” Scientific Reports (Aug 2023). https://doi.org/10.1038/s41598-023-40412-1 (masaki2023calcineurinmediateddephosphorylationenhances pages 1-2)
Vymazal O. et al. “Calcineurin-NFAT signaling controls neutrophils’ ability of chemoattraction upon fungal infection.” J Leukoc Biol (Apr 2024). https://doi.org/10.1093/jleuko/qiae091 (vymazal2024calcineurinnfatsignalingcontrols pages 1-2)
Fonódi M. et al. “Role of Protein Phosphatases in Tumor Angiogenesis…” IJMS (Jun 2024). https://doi.org/10.3390/ijms25136868 (fonodi2024roleofprotein pages 15-16)
ClinicalTrials.gov: NCT00270634 https://clinicaltrials.gov/study/NCT00270634 (NCT00270634 chunk 1)
ClinicalTrials.gov: NCT01429844 https://clinicaltrials.gov/study/NCT01429844 (NCT01429844 chunk 1)
ClinicalTrials.gov: NCT00038948 https://clinicaltrials.gov/study/NCT00038948 (NCT00038948 chunk 1)

References

(castiglioni2024expandingtheclinical pages 1-3): Silvia Castiglioni, Laura Pezzoli, Lidia Pezzani, Antonella Lettieri, Elisabetta Di Fede, Anna Cereda, Silvia Ancona, Andrea Gallina, Elisa Adele Colombo, Chiara Parodi, Paolo Grazioli, Esi Taci, Donatella Milani, Maria Iascone, Valentina Massa, and Cristina Gervasini. Expanding the clinical spectrum of ppp3ca variants - alternative isoforms matter. Orphanet Journal of Rare Diseases, Dec 2024. URL: https://doi.org/10.1186/s13023-024-03507-0, doi:10.1186/s13023-024-03507-0. This article has 3 citations and is from a peer-reviewed journal.
(lim2023calcineurinsignallingin pages 2-4): Dmitry Lim, Laura Tapella, Giulia Dematteis, Maria Talmon, and Armando A. Genazzani. Calcineurin signalling in astrocytes: from pathology to physiology and control of neuronal functions. Neurochemical Research, 48:1077-1090, Sep 2023. URL: https://doi.org/10.1007/s11064-022-03744-4, doi:10.1007/s11064-022-03744-4. This article has 35 citations and is from a peer-reviewed journal.
(nolze2023calcineurinisa pages 3-4): Alexander Nolze, Sebastian Matern, and Claudia Grossmann. Calcineurin is a universal regulator of vessel function—focus on vascular smooth muscle cells. Cells, 12:2269, Sep 2023. URL: https://doi.org/10.3390/cells12182269, doi:10.3390/cells12182269. This article has 14 citations.
(fonodi2024roleofprotein pages 15-16): Márton Fonódi, Lilla Nagy, and Anita Boratkó. Role of protein phosphatases in tumor angiogenesis: assessing pp1, pp2a, pp2b and ptps activity. International Journal of Molecular Sciences, 25:6868, Jun 2024. URL: https://doi.org/10.3390/ijms25136868, doi:10.3390/ijms25136868. This article has 10 citations.
(castiglioni2024expandingtheclinical media 7cdbd3c3): Silvia Castiglioni, Laura Pezzoli, Lidia Pezzani, Antonella Lettieri, Elisabetta Di Fede, Anna Cereda, Silvia Ancona, Andrea Gallina, Elisa Adele Colombo, Chiara Parodi, Paolo Grazioli, Esi Taci, Donatella Milani, Maria Iascone, Valentina Massa, and Cristina Gervasini. Expanding the clinical spectrum of ppp3ca variants - alternative isoforms matter. Orphanet Journal of Rare Diseases, Dec 2024. URL: https://doi.org/10.1186/s13023-024-03507-0, doi:10.1186/s13023-024-03507-0. This article has 3 citations and is from a peer-reviewed journal.
(masaki2023calcineurinmediateddephosphorylationenhances pages 1-2): Takahiro Masaki, Makoto Habara, Shunsuke Hanaki, Yuki Sato, Haruki Tomiyasu, Yosei Miki, and Midori Shimada. Calcineurin-mediated dephosphorylation enhances the stability and transactivation of c-myc. Scientific Reports, Aug 2023. URL: https://doi.org/10.1038/s41598-023-40412-1, doi:10.1038/s41598-023-40412-1. This article has 9 citations and is from a peer-reviewed journal.
(nolze2023calcineurinisa pages 4-5): Alexander Nolze, Sebastian Matern, and Claudia Grossmann. Calcineurin is a universal regulator of vessel function—focus on vascular smooth muscle cells. Cells, 12:2269, Sep 2023. URL: https://doi.org/10.3390/cells12182269, doi:10.3390/cells12182269. This article has 14 citations.
(nolze2023calcineurinisa pages 16-18): Alexander Nolze, Sebastian Matern, and Claudia Grossmann. Calcineurin is a universal regulator of vessel function—focus on vascular smooth muscle cells. Cells, 12:2269, Sep 2023. URL: https://doi.org/10.3390/cells12182269, doi:10.3390/cells12182269. This article has 14 citations.
(castiglioni2024expandingtheclinical pages 4-5): Silvia Castiglioni, Laura Pezzoli, Lidia Pezzani, Antonella Lettieri, Elisabetta Di Fede, Anna Cereda, Silvia Ancona, Andrea Gallina, Elisa Adele Colombo, Chiara Parodi, Paolo Grazioli, Esi Taci, Donatella Milani, Maria Iascone, Valentina Massa, and Cristina Gervasini. Expanding the clinical spectrum of ppp3ca variants - alternative isoforms matter. Orphanet Journal of Rare Diseases, Dec 2024. URL: https://doi.org/10.1186/s13023-024-03507-0, doi:10.1186/s13023-024-03507-0. This article has 3 citations and is from a peer-reviewed journal.
(castiglioni2024expandingtheclinical pages 5-7): Silvia Castiglioni, Laura Pezzoli, Lidia Pezzani, Antonella Lettieri, Elisabetta Di Fede, Anna Cereda, Silvia Ancona, Andrea Gallina, Elisa Adele Colombo, Chiara Parodi, Paolo Grazioli, Esi Taci, Donatella Milani, Maria Iascone, Valentina Massa, and Cristina Gervasini. Expanding the clinical spectrum of ppp3ca variants - alternative isoforms matter. Orphanet Journal of Rare Diseases, Dec 2024. URL: https://doi.org/10.1186/s13023-024-03507-0, doi:10.1186/s13023-024-03507-0. This article has 3 citations and is from a peer-reviewed journal.
(vymazal2024calcineurinnfatsignalingcontrols pages 1-2): Ondrej Vymazal, Ioanna Papatheodorou, Ivana Andrejčinová, Veronika Bosáková, Gianluca Vascelli, Kamila Bendíčková, Teresa Zelante, Marcela Hortová-Kohoutková, and Jan Frič. Calcineurin-nfat signaling controls neutrophils’ ability of chemoattraction upon fungal infection. Journal of Leukocyte Biology, 116:816-829, Apr 2024. URL: https://doi.org/10.1093/jleuko/qiae091, doi:10.1093/jleuko/qiae091. This article has 6 citations and is from a peer-reviewed journal.
(ashinze2025voclosporinacomprehensive pages 1-2): Patrick Ashinze, Nelson Mafua, Suvam Banerjee, Eniola Obafemi, Akande Eniola, Egbunu Emmanuel, Akogwu Ocholi Edache, Chukwu Bethrand Ozioma, Andrew Awuah Wireko, and Toufik Abdul-Rahman. Voclosporin: a comprehensive review of its role as a novel calcineurin inhibitor in the management of systemic lupus erythematosus. Medicine, 104:e42858, Jun 2025. URL: https://doi.org/10.1097/md.0000000000042858, doi:10.1097/md.0000000000042858. This article has 3 citations and is from a peer-reviewed journal.
(wu2026efficacyandsafety pages 1-2): Yan Wu, Wenting Cai, Yao Yao, and Jinping Zhang. Efficacy and safety of calcineurin inhibitor therapy in lupus nephritis: a systematic review and network meta-analysis. Frontiers in Immunology, Jan 2026. URL: https://doi.org/10.3389/fimmu.2025.1670134, doi:10.3389/fimmu.2025.1670134. This article has 0 citations and is from a peer-reviewed journal.
(NCT00270634 chunk 1): Study of ISA247 (Voclosporin) in De Novo Renal Transplantation. Aurinia Pharmaceuticals Inc.. 2006. ClinicalTrials.gov Identifier: NCT00270634
(NCT01429844 chunk 1): Prof. Dr. Hermann Reichenspurner. Tacrolimus Versus Cyclosporine for Immunosuppression After Lung Transplantation. Universitätsklinikum Hamburg-Eppendorf. 2001. ClinicalTrials.gov Identifier: NCT01429844
(NCT00038948 chunk 1): Study Comparing Conversion to Sirolimus vs. Continued Use of Calcineurin Inhibitors in Kidney Transplant Recipients. Wyeth is now a wholly owned subsidiary of Pfizer. 2002. ClinicalTrials.gov Identifier: NCT00038948
(NCT00270634 chunk 2): Study of ISA247 (Voclosporin) in De Novo Renal Transplantation. Aurinia Pharmaceuticals Inc.. 2006. ClinicalTrials.gov Identifier: NCT00270634

Citations

lim2023calcineurinsignallingin pages 2-4
fonodi2024roleofprotein pages 15-16
castiglioni2024expandingtheclinical pages 1-3
nolze2023calcineurinisa pages 4-5
nolze2023calcineurinisa pages 3-4
masaki2023calcineurinmediateddephosphorylationenhances pages 1-2
castiglioni2024expandingtheclinical pages 4-5
castiglioni2024expandingtheclinical pages 5-7
vymazal2024calcineurinnfatsignalingcontrols pages 1-2
ashinze2025voclosporinacomprehensive pages 1-2
wu2026efficacyandsafety pages 1-2
nolze2023calcineurinisa pages 16-18
https://doi.org/10.1007/s11064-022-03744-4;
https://doi.org/10.1186/s13023-024-03507-0
https://doi.org/10.1007/s11064-022-03744-4
https://doi.org/10.3390/ijms25136868;
https://doi.org/10.3390/cells12182269;
https://doi.org/10.1038/s41598-023-40412-1
https://doi.org/10.3390/cells12182269
https://doi.org/10.1186/s13023-024-03507-0;
https://doi.org/10.1097/md.0000000000042858;
https://doi.org/10.3389/fimmu.2025.1670134
https://clinicaltrials.gov/study/NCT00270634
https://clinicaltrials.gov/study/NCT01429844
https://clinicaltrials.gov/study/NCT00038948
https://doi.org/10.1097/md.0000000000042858
https://doi.org/10.1093/jleuko/qiae091
https://doi.org/10.3390/ijms25136868
https://doi.org/10.1186/s13023-024-03507-0,
https://doi.org/10.1007/s11064-022-03744-4,
https://doi.org/10.3390/cells12182269,
https://doi.org/10.3390/ijms25136868,
https://doi.org/10.1038/s41598-023-40412-1,
https://doi.org/10.1093/jleuko/qiae091,
https://doi.org/10.1097/md.0000000000042858,
https://doi.org/10.3389/fimmu.2025.1670134,

📄 View Raw YAML

id: Q08209
gene_symbol: PPP3CA
product_type: PROTEIN
status: DRAFT
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: PPP3CA encodes calcineurin catalytic subunit A alpha, a calcium/calmodulin-activated serine/threonine phosphatase (EC 3.1.3.16) that functions in the calcineurin holoenzyme to dephosphorylate signaling substrates including NFAT-family transcription factors. Its core roles are phosphoprotein dephosphorylation and calcineurin-NFAT pathway signaling, with additional context-dependent functions in neuronal, immune, muscle, and renal physiology.
alternative_products:
- name: '1'
  id: Q08209-1
- name: '2'
  id: Q08209-2
  sequence_note: VSP_018562
- name: '3'
  id: Q08209-3
  sequence_note: VSP_043378, VSP_018562
- name: '4'
  id: Q08209-4
  sequence_note: VSP_047755
- name: '5'
  id: Q08209-5
  sequence_note: VSP_054467
existing_annotations:
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722].
    action: ACCEPT
    reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
    supported_by:
    - reference_id: file:human/PPP3CA/PPP3CA-deep-research-falcon.md
      supporting_text: 'model: Edison Scientific Literature'
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0004722
    label: protein serine/threonine phosphatase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414].
    action: ACCEPT
    reason: This is a core molecular-function annotation directly matching the known enzyme class.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722].
    action: ACCEPT
    reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
- term:
    id: GO:0016787
    label: hydrolase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: Hydrolase activity is correct but overly broad for PPP3CA.
    action: MODIFY
    reason: A more specific phosphatase term better represents known catalytic chemistry for calcineurin A alpha.
    proposed_replacement_terms:
    - id: GO:0004722
      label: protein serine/threonine phosphatase activity
    - id: GO:0033192
      label: calmodulin-dependent protein phosphatase activity
- term:
    id: GO:0030018
    label: Z disc
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: Z-disc association is described in muscle-context interaction studies [PMID:11114196, PMID:11842093].
    action: KEEP_AS_NON_CORE
    reason: Contextual localization in muscle; not a universal core location.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0042383
    label: sarcolemma
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: Sarcolemma localization is supported in muscle-related contexts [PMID:15955804].
    action: KEEP_AS_NON_CORE
    reason: Context-specific localization; not the most general core compartment term.
- term:
    id: GO:0043197
    label: dendritic spine
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: Dendritic-spine localization is plausible in neuronal signaling contexts [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Supported in specific cellular contexts but not a universal core localization.
- term:
    id: GO:0097720
    label: calcineurin-mediated signaling
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: Calcineurin-mediated signaling is a direct and central biological-process role of PPP3CA.
    action: ACCEPT
    reason: This is a core pathway-level annotation aligned with extensive calcineurin literature.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12577067
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16189514
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:17474147
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19896943
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:21900206
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24418105
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25416956
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32814053
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:37398436
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:8524402
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: NAS
  original_reference_id: PMID:22343722
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: NAS
  original_reference_id: PMID:28126489
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0070886
    label: positive regulation of calcineurin-NFAT signaling cascade
  evidence_type: NAS
  original_reference_id: PMID:22343722
  review:
    summary: PPP3CA activity supports NFAT activation and therefore positive regulation of calcineurin-NFAT signaling [PMID:22343722, PMID:8631904].
    action: ACCEPT
    reason: Term is consistent with known pathway directionality for calcineurin catalytic function.
- term:
    id: GO:0070886
    label: positive regulation of calcineurin-NFAT signaling cascade
  evidence_type: NAS
  original_reference_id: PMID:8631904
  review:
    summary: PPP3CA activity supports NFAT activation and therefore positive regulation of calcineurin-NFAT signaling [PMID:22343722, PMID:8631904].
    action: ACCEPT
    reason: Term is consistent with known pathway directionality for calcineurin catalytic function.
- term:
    id: GO:1905665
    label: positive regulation of calcium ion import across plasma membrane
  evidence_type: NAS
  original_reference_id: PMID:17640527
  review:
    summary: Directional regulation of calcium import is highly context-dependent and potentially conflicting across systems.
    action: MARK_AS_OVER_ANNOTATED
    reason: Process-level directionality is not robust as a core PPP3CA annotation.
- term:
    id: GO:1905949
    label: negative regulation of calcium ion import across plasma membrane
  evidence_type: NAS
  original_reference_id: PMID:17640527
  review:
    summary: Directional regulation of calcium import is highly context-dependent and potentially conflicting across systems.
    action: MARK_AS_OVER_ANNOTATED
    reason: Process-level directionality is not robust as a core PPP3CA annotation.
- term:
    id: GO:0004722
    label: protein serine/threonine phosphatase activity
  evidence_type: IMP
  original_reference_id: PMID:30611118
  review:
    summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414].
    action: ACCEPT
    reason: This is a core molecular-function annotation directly matching the known enzyme class.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IDA
  original_reference_id: GO_REF:0000052
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:1903235
    label: positive regulation of calcium ion-dependent exocytosis of neurotransmitter
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Neuronal exocytosis-regulation linkage is plausible in synaptic calcineurin signaling.
    action: KEEP_AS_NON_CORE
    reason: Likely context-dependent downstream physiology rather than universally core.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IDA
  original_reference_id: PMID:30718414
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0110062
    label: negative regulation of angiotensin-activated signaling pathway
  evidence_type: IDA
  original_reference_id: PMID:30718414
  review:
    summary: Supported kidney signaling context where calcineurin opposes angiotensin-driven phosphorylation events [PMID:30718414].
    action: KEEP_AS_NON_CORE
    reason: Evidence is strong but process scope is context-specific rather than core pan-context function.
- term:
    id: GO:0004722
    label: protein serine/threonine phosphatase activity
  evidence_type: IDA
  original_reference_id: PMID:30718414
  review:
    summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414].
    action: ACCEPT
    reason: This is a core molecular-function annotation directly matching the known enzyme class.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: EXP
  original_reference_id: PMID:18384083
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IDA
  original_reference_id: PMID:18384083
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IPI
  original_reference_id: PMID:18384083
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: EXP
  original_reference_id: PMID:24191726
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IPI
  original_reference_id: PMID:24191726
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: EXP
  original_reference_id: PMID:27187005
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:34446558
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0042104
    label: positive regulation of activated T cell proliferation
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Calcineurin signaling contributes to activated T-cell proliferation, but this is a higher-level physiological context.
    action: KEEP_AS_NON_CORE
    reason: Biologically plausible yet not the most direct core process label for PPP3CA.
- term:
    id: GO:0023057
    label: negative regulation of signaling
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Negative regulation of signaling is too broad as a standalone process attribution for PPP3CA.
    action: MARK_AS_OVER_ANNOTATED
    reason: PPP3CA can both positively and negatively affect distinct pathways depending on substrate/context.
- term:
    id: GO:0050804
    label: modulation of chemical synaptic transmission
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Chemical synaptic transmission modulation is plausible in neuronal calcineurin signaling contexts.
    action: KEEP_AS_NON_CORE
    reason: Kept as non-core because it is a broad downstream neurophysiology term.
- term:
    id: GO:0008544
    label: epidermis development
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Epidermis-development links are mostly orthology/context-derived and represent peripheral biology for PPP3CA.
    action: KEEP_AS_NON_CORE
    reason: Retained as non-core because evidence is not the strongest direct core-function signal for human PPP3CA.
- term:
    id: GO:0030216
    label: keratinocyte differentiation
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Keratinocyte differentiation linkage is plausible but peripheral relative to core calcineurin signaling.
    action: KEEP_AS_NON_CORE
    reason: Evidence is largely contextual/orthology-backed rather than primary core-function evidence.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:28881575
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:28881575
  review:
    summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
- term:
    id: GO:0097205
    label: renal filtration
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Renal filtration linkage is consistent with kidney-context calcineurin roles.
    action: KEEP_AS_NON_CORE
    reason: Kept as non-core because this is tissue-physiology-level rather than direct molecular process annotation.
- term:
    id: GO:0046878
    label: positive regulation of saliva secretion
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Saliva-secretion annotation represents specialized tissue physiology rather than core function.
    action: KEEP_AS_NON_CORE
    reason: Retained as non-core due restricted physiological context.
- term:
    id: GO:0061006
    label: regulation of cell proliferation involved in kidney morphogenesis
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Kidney morphogenesis/cell proliferation links are plausible but represent specific developmental context.
    action: KEEP_AS_NON_CORE
    reason: Retained as non-core due context specificity and indirectness.
- term:
    id: GO:0090193
    label: positive regulation of glomerulus development
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Positive regulation of glomerulus development is plausible from renal calcineurin biology.
    action: KEEP_AS_NON_CORE
    reason: Non-core developmental physiology term for PPP3CA.
- term:
    id: GO:0048741
    label: skeletal muscle fiber development
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Skeletal-muscle-fiber development effects are plausible but peripheral to core enzymatic function.
    action: KEEP_AS_NON_CORE
    reason: Represents context-dependent developmental biology rather than central molecular role.
- term:
    id: GO:0045672
    label: positive regulation of osteoclast differentiation
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Osteoclast differentiation via calcineurin-NFAT is plausible but context-specific.
    action: KEEP_AS_NON_CORE
    reason: Not core across all major PPP3CA biological contexts.
- term:
    id: GO:0045669
    label: positive regulation of osteoblast differentiation
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Osteoblast-differentiation effects are plausible calcineurin/NFAT downstream physiology.
    action: KEEP_AS_NON_CORE
    reason: Kept as non-core due indirect/process-level specificity.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IMP
  original_reference_id: PMID:30254215
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IMP
  original_reference_id: PMID:26248042
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0097720
    label: calcineurin-mediated signaling
  evidence_type: IMP
  original_reference_id: PMID:11005320
  review:
    summary: Calcineurin-mediated signaling is a direct and central biological-process role of PPP3CA.
    action: ACCEPT
    reason: This is a core pathway-level annotation aligned with extensive calcineurin literature.
- term:
    id: GO:0042060
    label: wound healing
  evidence_type: TAS
  original_reference_id: PMID:18846255
  review:
    summary: Wound-healing links reflect downstream physiological contexts of calcineurin/NFAT signaling.
    action: KEEP_AS_NON_CORE
    reason: Not a specific core process assignment for PPP3CA itself.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IDA
  original_reference_id: PMID:15955804
  review:
    summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722].
    action: ACCEPT
    reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:15955804
  review:
    summary: PPP3CA can be recruited to the plasma membrane by scaffolds such as AKAP79 [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Membrane recruitment is experimentally supported but is context-dependent rather than the universal core state.
- term:
    id: GO:0019897
    label: extrinsic component of plasma membrane
  evidence_type: IC
  original_reference_id: PMID:15955804
  review:
    summary: Extrinsic plasma-membrane association can occur via scaffolded complexes [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Valid in specific contexts, but not the principal localization state.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IMP
  original_reference_id: PMID:15955804
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0051117
    label: ATPase binding
  evidence_type: IPI
  original_reference_id: PMID:15955804
  review:
    summary: ATPase binding is plausible from interaction studies but secondary to phosphatase catalytic function.
    action: KEEP_AS_NON_CORE
    reason: Valid interaction-level annotation with limited functional specificity.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:30611118
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0043403
    label: skeletal muscle tissue regeneration
  evidence_type: TAS
  original_reference_id: PMID:18846255
  review:
    summary: Skeletal-muscle regeneration links are plausible but reflect specialized physiological settings.
    action: KEEP_AS_NON_CORE
    reason: Not a primary core process for broad PPP3CA function assignment.
- term:
    id: GO:0045785
    label: positive regulation of cell adhesion
  evidence_type: IMP
  original_reference_id: PMID:21785830
  review:
    summary: Positive regulation of cell adhesion appears mainly from disease/cell-line contexts.
    action: MARK_AS_OVER_ANNOTATED
    reason: Likely over-extended from context-specific phenotypes rather than core PPP3CA role.
- term:
    id: GO:0030335
    label: positive regulation of cell migration
  evidence_type: IMP
  original_reference_id: PMID:21785830
  review:
    summary: Positive regulation of cell migration is supported mainly by cancer-context perturbation studies [PMID:20422345, PMID:21785830].
    action: MARK_AS_OVER_ANNOTATED
    reason: Likely context-specific/pleiotropic and not a robust core function term for PPP3CA.
- term:
    id: GO:0030335
    label: positive regulation of cell migration
  evidence_type: IMP
  original_reference_id: PMID:20422345
  review:
    summary: Positive regulation of cell migration is supported mainly by cancer-context perturbation studies [PMID:20422345, PMID:21785830].
    action: MARK_AS_OVER_ANNOTATED
    reason: Likely context-specific/pleiotropic and not a robust core function term for PPP3CA.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:18218901
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12809556
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12218175
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:26248042
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:27974827
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IDA
  original_reference_id: PMID:19404396
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IDA
  original_reference_id: PMID:19154138
  review:
    summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722].
    action: ACCEPT
    reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IDA
  original_reference_id: PMID:22343722
  review:
    summary: Cytoplasmic localization is consistent with established PPP3CA signaling biology [PMID:19154138, PMID:22343722].
    action: ACCEPT
    reason: PPP3CA acts on cytoplasmic signaling substrates and scaffolded signaling complexes.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:12218175
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:22343722
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:23468591
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:27974827
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0006470
    label: protein dephosphorylation
  evidence_type: IDA
  original_reference_id: PMID:19154138
  review:
    summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414].
    action: ACCEPT
    reason: This accurately reflects catalytic activity on phosphoprotein substrates.
- term:
    id: GO:0009898
    label: cytoplasmic side of plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:22343722
  review:
    summary: PPP3CA can localize on the cytoplasmic side of membrane-associated signaling complexes [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Supported by scaffolded signaling, but context-specific.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IDA
  original_reference_id: PMID:19154138
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IMP
  original_reference_id: PMID:22343722
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IMP
  original_reference_id: PMID:23468591
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IDA
  original_reference_id: PMID:19154138
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IDA
  original_reference_id: PMID:23468591
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0043197
    label: dendritic spine
  evidence_type: IDA
  original_reference_id: PMID:22343722
  review:
    summary: Dendritic-spine localization is plausible in neuronal signaling contexts [PMID:22343722].
    action: KEEP_AS_NON_CORE
    reason: Supported in specific cellular contexts but not a universal core localization.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12357034
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:12357034
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:22688515
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: IDA
  original_reference_id: PMID:22688515
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
- term:
    id: GO:0033173
    label: calcineurin-NFAT signaling cascade
  evidence_type: IDA
  original_reference_id: PMID:22688515
  review:
    summary: PPP3CA is a core mediator of calcineurin-NFAT signaling through NFAT dephosphorylation [PMID:22343722, PMID:26248042, PMID:8631904].
    action: ACCEPT
    reason: NFAT-pathway coupling is a principal validated function of calcineurin catalytic subunits.
- term:
    id: GO:0045944
    label: positive regulation of transcription by RNA polymerase II
  evidence_type: IDA
  original_reference_id: PMID:22688515
  review:
    summary: PPP3CA can promote transcription indirectly through NFAT dephosphorylation and nuclear translocation [PMID:22688515].
    action: KEEP_AS_NON_CORE
    reason: Downstream regulatory consequence, not direct transcription-factor molecular function.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2025890
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2730849
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2730867
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2730872
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-4551451
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-4551465
  review:
    summary: PPP3CA/calcineurin functions in the cytosol in Ca2+-dependent signaling complexes [PMID:22343722].
    action: ACCEPT
    reason: Cytosolic localization is consistent with canonical calcineurin signaling and substrate dephosphorylation.
- term:
    id: GO:0005654
    label: nucleoplasm
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2730867
  review:
    summary: Nucleoplasmic context can occur during NFAT-related signaling translocation events (Reactome evidence).
    action: KEEP_AS_NON_CORE
    reason: Reasonable pathway-context localization, but less central than cytosolic/calcineurin-complex roles.
- term:
    id: GO:0005654
    label: nucleoplasm
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-4551465
  review:
    summary: Nucleoplasmic context can occur during NFAT-related signaling translocation events (Reactome evidence).
    action: KEEP_AS_NON_CORE
    reason: Reasonable pathway-context localization, but less central than cytosolic/calcineurin-complex roles.
- term:
    id: GO:0006470
    label: protein dephosphorylation
  evidence_type: IDA
  original_reference_id: PMID:18815128
  review:
    summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414].
    action: ACCEPT
    reason: This accurately reflects catalytic activity on phosphoprotein substrates.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: IDA
  original_reference_id: PMID:18815128
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0051592
    label: response to calcium ion
  evidence_type: IDA
  original_reference_id: PMID:18815128
  review:
    summary: PPP3CA is activated by intracellular calcium signaling and participates in calcium-responsive pathways.
    action: ACCEPT
    reason: This broad process term is directionally consistent with calcineurin biology.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IDA
  original_reference_id: PMID:11005320
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0019899
    label: enzyme binding
  evidence_type: IDA
  original_reference_id: PMID:11005320
  review:
    summary: PPP3CA binds multiple enzyme partners/regulators, but this term is broad and secondary to catalytic function.
    action: KEEP_AS_NON_CORE
    reason: Retained as non-core due limited specificity.
- term:
    id: GO:0042110
    label: T cell activation
  evidence_type: TAS
  original_reference_id: PMID:11005320
  review:
    summary: T-cell activation involvement is compatible with canonical calcineurin-immunology biology.
    action: KEEP_AS_NON_CORE
    reason: Retained as non-core due pathway-level context and isoform/redundancy considerations.
- term:
    id: GO:0046983
    label: protein dimerization activity
  evidence_type: IPI
  original_reference_id: PMID:11005320
  review:
    summary: Protein dimerization activity is not a well-supported or informative core MF for PPP3CA.
    action: REMOVE
    reason: Evidence better supports regulated complex assembly (calcineurin holoenzyme) rather than standalone dimerization activity.
- term:
    id: GO:0016311
    label: dephosphorylation
  evidence_type: TAS
  original_reference_id: PMID:2556704
  review:
    summary: Dephosphorylation is the defining catalytic process of PPP3CA/calcineurin.
    action: ACCEPT
    reason: Accurately reflects direct enzyme activity.
- term:
    id: GO:0033192
    label: calmodulin-dependent protein phosphatase activity
  evidence_type: TAS
  original_reference_id: PMID:2556704
  review:
    summary: PPP3CA is a calmodulin-dependent serine/threonine phosphatase (calcineurin) [PMID:19154138, PMID:23468591].
    action: ACCEPT
    reason: This term captures the specific enzymatic mechanism of PPP3CA.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:18838687
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:11114196
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:11842093
  review:
    summary: Generic protein-binding annotations from interaction screens are not functionally informative for PPP3CA.
    action: REMOVE
    reason: PPP3CA has many interaction partners, but GO:0005515 does not capture its specific calcineurin phosphatase function or pathway role.
- term:
    id: GO:0006470
    label: protein dephosphorylation
  evidence_type: NAS
  original_reference_id: PMID:8392375
  review:
    summary: Protein dephosphorylation is the direct biochemical output of PPP3CA/calcineurin [PMID:15671020, PMID:30718414].
    action: ACCEPT
    reason: This accurately reflects catalytic activity on phosphoprotein substrates.
- term:
    id: GO:0004722
    label: protein serine/threonine phosphatase activity
  evidence_type: NAS
  original_reference_id: PMID:8392375
  review:
    summary: PPP3CA is a protein serine/threonine phosphatase catalytic subunit [PMID:19154138, PMID:30718414].
    action: ACCEPT
    reason: This is a core molecular-function annotation directly matching the known enzyme class.
- term:
    id: GO:0005509
    label: calcium ion binding
  evidence_type: NAS
  original_reference_id: PMID:8392375
  review:
    summary: Direct calcium-ion binding by PPP3CA catalytic subunit is less specific than calmodulin-dependent activation and holoenzyme regulation.
    action: MARK_AS_OVER_ANNOTATED
    reason: Annotation is plausible at a broad level but overstates direct, independently informative MF for PPP3CA.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: NAS
  original_reference_id: PMID:8392375
  review:
    summary: Calmodulin binding is central to calcineurin activation and is well supported for PPP3CA [PMID:18384083, PMID:19404396].
    action: ACCEPT
    reason: PPP3CA activation requires Ca2+/calmodulin-dependent engagement of its regulatory region, making this a core molecular function.
- term:
    id: GO:0005955
    label: calcineurin complex
  evidence_type: NAS
  original_reference_id: PMID:8392375
  review:
    summary: PPP3CA is the catalytic subunit of the calcineurin complex [PMID:12218175, PMID:12357034, PMID:23468591].
    action: ACCEPT
    reason: Complex membership is definitive and foundational to PPP3CA biology.
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000024
  title: Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: GO_REF:0000052
  title: Gene Ontology annotation based on curation of immunofluorescence data
  findings: []
- id: GO_REF:0000117
  title: Electronic Gene Ontology annotations created by ARBA machine learning models
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:11005320
  title: Genetic conservation of the immunophilin-binding domains of human calcineurin A1 and A2.
  findings: []
- id: PMID:11114196
  title: Calsarcins, a novel family of sarcomeric calcineurin-binding proteins.
  findings: []
- id: PMID:11842093
  title: Calsarcin-3, a novel skeletal muscle-specific member of the calsarcin family, interacts with multiple Z-disc proteins.
  findings: []
- id: PMID:12218175
  title: Crystal structure of calcineurin-cyclophilin-cyclosporin shows common but distinct recognition of immunophilin-drug complexes.
  findings: []
- id: PMID:12357034
  title: Crystal structure of human calcineurin complexed with cyclosporin A and human cyclophilin.
  findings: []
- id: PMID:12577067
  title: A proteomics strategy to elucidate functional protein-protein interactions applied to EGF signaling.
  findings: []
- id: PMID:12809556
  title: Phosphorylation of calcipressin 1 increases its ability to inhibit calcineurin and decreases calcipressin half-life.
  findings: []
- id: PMID:15955804
  title: The sarcolemmal calcium pump inhibits the calcineurin/nuclear factor of activated T-cell pathway via interaction with the calcineurin A catalytic subunit.
  findings: []
- id: PMID:16189514
  title: Towards a proteome-scale map of the human protein-protein interaction network.
  findings: []
- id: PMID:17474147
  title: Systematic identification of SH3 domain-mediated human protein-protein interactions by peptide array target screening.
  findings: []
- id: PMID:17640527
  title: AKAP79/150 anchoring of calcineurin controls neuronal L-type Ca2+ channel activity and nuclear signaling.
  findings: []
- id: PMID:18218901
  title: NFAT binding and regulation of T cell activation by the cytoplasmic scaffolding Homer proteins.
  findings: []
- id: PMID:18384083
  title: The complex structure of calmodulin bound to a calcineurin peptide.
  findings: []
- id: PMID:18815128
  title: CHP2 activates the calcineurin/nuclear factor of activated T cells signaling pathway and enhances the oncogenic potential of HEK293 cells.
  findings: []
- id: PMID:18838687
  title: Dephosphorylation by calcineurin regulates translocation of Drp1 to mitochondria.
  findings: []
- id: PMID:18846255
  title: Calsarcin-2 deficiency increases exercise capacity in mice through calcineurin/NFAT activation.
  findings: []
- id: PMID:19154138
  title: The proline-rich N-terminal sequence of calcineurin Abeta determines substrate binding.
  findings: []
- id: PMID:19404396
  title: Domain swapping and different oligomeric States for the complex between calmodulin and the calmodulin-binding domain of calcineurin a.
  findings: []
- id: PMID:19896943
  title: 'WITHDRAWN: USP14 stabilizes calcineurin and regulates NFAT/AP-1 dependent IL-4 transcription as a novel calcineurin-binding protein.'
  findings: []
- id: PMID:20422345
  title: Calcineurin promotes proliferation, migration, and invasion of small cell lung cancer.
  findings: []
- id: PMID:21785830
  title: The effect of down regulation of calcineurin Aα by lentiviral vector-mediated RNAi on the biological behavior of small-cell lung cancer and its bone metastasis.
  findings: []
- id: PMID:21900206
  title: A directed protein interaction network for investigating intracellular signal transduction.
  findings: []
- id: PMID:22343722
  title: Balanced interactions of calcineurin with AKAP79 regulate Ca2+-calcineurin-NFAT signaling.
  findings: []
- id: PMID:22688515
  title: Na(+)/H(+) exchanger 1 directly binds to calcineurin A and activates downstream NFAT signaling, leading to cardiomyocyte hypertrophy.
  findings: []
- id: PMID:23468591
  title: The molecular mechanism of substrate engagement and immunosuppressant inhibition of calcineurin.
  findings: []
- id: PMID:24191726
  title: The distal helix in the regulatory domain of calcineurin is important for domain stability and enzyme function.
  findings: []
- id: PMID:24418105
  title: Direct association of the unique C-terminal tail of transmembrane AMPA receptor regulatory protein γ-8 with calcineurin.
  findings: []
- id: PMID:25416956
  title: A proteome-scale map of the human interactome network.
  findings: []
- id: PMID:2556704
  title: 'Cloning of human calcineurin A: evidence for two isozymes and identification of a polyproline structural domain.'
  findings: []
- id: PMID:26248042
  title: Calcineurin Undergoes a Conformational Switch Evoked via Peptidyl-Prolyl Isomerization.
  findings: []
- id: PMID:27187005
  title: Calcineurin in a Crowded World.
  findings: []
- id: PMID:27974827
  title: Investigating the human Calcineurin Interaction Network using the πɸLxVP SLiM.
  findings: []
- id: PMID:28126489
  title: 'The protein serine/threonine phosphatases PP2A, PP1 and calcineurin: A triple threat in the regulation of the neuronal cytoskeleton.'
  findings: []
- id: PMID:28881575
  title: Overexpression of C16orf74 is involved in aggressive pancreatic cancers.
  findings: []
- id: PMID:30254215
  title: Novel calcineurin A (PPP3CA) variant associated with epilepsy, constitutive enzyme activation and downregulation of protein expression.
  findings: []
- id: PMID:30611118
  title: Mitogenic Signals Stimulate the CREB Coactivator CRTC3 through PP2A Recruitment.
  findings: []
- id: PMID:30718414
  title: Calcineurin dephosphorylates Kelch-like 3, reversing phosphorylation by angiotensin II and regulating renal electrolyte handling.
  findings: []
- id: PMID:32814053
  title: Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.
  findings: []
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
  findings: []
- id: PMID:34446558
  title: SPATA33 localizes calcineurin to the mitochondria and regulates sperm motility in mice.
  findings: []
- id: PMID:37398436
  title: AI-guided pipeline for protein-protein interaction drug discovery identifies a SARS-CoV-2 inhibitor.
  findings: []
- id: PMID:8392375
  title: Molecular cloning of a full-length cDNA encoding the catalytic subunit of human calmodulin-dependent protein phosphatase (calcineurin A alpha).
  findings: []
- id: PMID:8524402
  title: Crystal structures of human calcineurin and the human FKBP12-FK506-calcineurin complex.
  findings: []
- id: PMID:8631904
  title: Calcineurin binds the transcription factor NFAT1 and reversibly regulates its activity.
  findings: []
- id: Reactome:R-HSA-2025890
  title: Calcineurin binds NFATC1,2,3
  findings: []
- id: Reactome:R-HSA-2730849
  title: Calcineurin binds and dephosphorylates NFAT
  findings: []
- id: Reactome:R-HSA-2730867
  title: Translocation of CaN:CaM:NFAT to nucleus
  findings: []
- id: Reactome:R-HSA-2730872
  title: Activation of Calcineurin
  findings: []
- id: Reactome:R-HSA-4551451
  title: Calcineurin binds and dephosphorylates NFAT1 in response to WNT/Ca2+ signaling
  findings: []
- id: Reactome:R-HSA-4551465
  title: Translocation of NFATC1:CaN:CaM to nucleus
  findings: []
- id: file:human/PPP3CA/PPP3CA-deep-research-falcon.md
  title: Deep research report on PPP3CA
  findings: []

PPP3CA

Gene Description

Existing Annotations Review

References

Deep Research

Falcon

Research Report: Human PPP3CA (UniProt Q08209) — Functional Annotation of Calcineurin Aα (PP2B catalytic subunit)

1. Target verification and gene/protein identity

2. Key concepts and current mechanistic understanding

2.1. Enzymatic function (reaction class and specificity)

2.2. Holoenzyme architecture, domains, and activation by Ca2+/calmodulin

2.3. PPP3CA isoforms (human) and domain layout (UniProt Q08209)

3. Pathways, biological processes, and cellular context

3.1. Canonical Ca2+–calcineurin–NFAT signaling

3.2. CNS/astrocyte signaling: calcineurin as a Ca2+-sensitive switch

3.3. Vascular smooth muscle and cardiovascular biology

3.4. Kidney biology and clinical renal contexts

4. Substrates and functional outputs (selected examples with experimental support)

4.1. c-Myc stability via direct dephosphorylation (primary evidence, 2023)

4.2. TFEB and autophagy/lysosomal biogenesis (pathway placement)

4.3. Synaptic receptors and Ca2+ handling proteins (systems-level role)

5. Recent developments (prioritizing 2023–2024)

5.1. 2024: PPP3CA variants and isoform-specific disease mechanisms

5.2. 2024: Calcineurin–NFAT signaling in human neutrophils and antifungal immunity

5.3. 2023–2024: Emerging mechanistic framing and therapeutic caveats

6. Current applications and real-world implementations

6.1. Calcineurin inhibitors (CNIs) as immunosuppressants and targeted anti-inflammatory agents

6.2. Lupus nephritis: voclosporin outcomes and comparative evidence

6.3. Clinical trial registry implementations (transplantation and beyond)

7. Expert synthesis and interpretation (authoritative-source grounded)

7.1. Why calcineurin is hard to “functionally annotate” as a single-target enzyme

7.2. Therapeutic implication: separating “NFAT biology” from “calcineurin biology”

8. Summary tables (for rapid reference)

9. Key source URLs (recent, authoritative)

Citations

📄 View Raw YAML