CCT4 encodes the delta subunit of the cytosolic chaperonin-containing T-complex (CCT/TRiC). CCT/TRiC is an ATP-dependent hetero-oligomeric chaperonin with two stacked rings built from eight related subunits. The complex assists folding of actin, tubulin, and other cytosolic substrates. CCT4 contributes as an integral subunit of the assembled CCT complex rather than as a free general protein-binding factor.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0006457 protein folding | IBA GO_REF:0000033 | ACCEPT | Summary: CCT4 is a subunit of the CCT/TRiC chaperonin, which catalyzes ATP-dependent folding of actin and other cytosolic substrates. Reason: Yeast CCT purified from cells folds yeast ACT1p and human beta-actin in vitro, and the CCT family assignment supports conserved chaperonin function. Supporting Evidence: PMID:16762366 Yeast CCT catalyses the folding of yeast ACT1p and human beta-actin with nearly identical rate constants and yields. file:interpro/panther/PTHR11353/PTHR11353-metadata.yaml PANTHER PTHR11353 classifies CCT4 in the chaperonin family. file:yeast/CCT4/CCT4-deep-research-falcon.md Falcon synthesis supports CCT4 as the CCT/TRiC delta subunit with conserved ATP-dependent chaperonin function. |
| GO:0005832 chaperonin-containing T-complex | IBA GO_REF:0000033 | ACCEPT | Summary: CCT4 is an integral CCT/TRiC subunit and the complex term is appropriate. Reason: The chaperonin-containing T-complex is composed of a stoichiometric array of Cct1p-Cct8p subunits, including Cct4p. Supporting Evidence: PMID:15704212 Eukaryotic chaperonins, the Cct complexes, are assembled into two rings, each of which is composed of a stoichiometric array of eight different subunits, which are denoted Cct1p-Cct8p. |
| GO:0051082 unfolded protein binding | IBA GO_REF:0000033 | MODIFY | Summary: GO:0051082 is formally obsolete; Cct4 contributes to the CCT/TRiC complex's ATP-dependent protein-folding chaperone activity. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct4, the evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct4 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Propagation Review Root cause: SOURCE STALE OR MISSING Failure modes: SOURCE EVIDENCE WEAK Sources checked: PANTHER:PTN004253040 · PAINT chaperonin node SOURCE STALE OR MISSING The current PTHR11353 PAINT record retains this node for conserved CCT/TRiC protein-folding biology, but it no longer carries obsolete GO:0051082 as a molecular-function IBD. Proposed replacements: ATP-dependent protein folding chaperone |
| GO:0000166 nucleotide binding | IEA GO_REF:0000043 | ACCEPT | Summary: CCT4 is a TCP-1 family chaperonin subunit with conserved nucleotide-binding machinery. Reason: ATP binding and hydrolysis are part of the CCT chaperonin cycle, but this broad keyword-derived term is retained as a valid molecular feature. Supporting Evidence: file:interpro/panther/PTHR11353/PTHR11353-metadata.yaml PTHR11353 is the conserved chaperonin family that includes TCP-1/CCT proteins. |
| GO:0005524 ATP binding | IEA GO_REF:0000120 | ACCEPT | Summary: ATP binding is consistent with the ATP-dependent CCT/TRiC chaperonin cycle. Reason: The complex is explicitly described as an ATP-dependent folding machine and CCT4 belongs to the ATPase-containing TCP-1 chaperonin family. Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine. |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: CCT4 functions in the cytosolic CCT/TRiC complex. Reason: UniProt and CCT chaperone literature place this chaperonin in the cytoplasm, where it folds cytosolic substrates such as actin and tubulin. |
| GO:0005832 chaperonin-containing T-complex | IEA GO_REF:0000117 | ACCEPT | Summary: ARBA annotation to the CCT complex is supported by the known subunit composition. Reason: CCT4/Cct4p is one of the Cct1p-Cct8p subunits of the chaperonin-containing T-complex. |
| GO:0006457 protein folding | IEA GO_REF:0000120 | ACCEPT | Summary: Protein folding is the core biological process of the CCT/TRiC complex. Reason: The term is broad but correct for this subunit because the assembled CCT complex catalyzes folding of actin and other substrates. |
| GO:0016887 ATP hydrolysis activity | IEA GO_REF:0000002 | ACCEPT | Summary: ATP hydrolysis activity is consistent with CCT/TRiC chaperonin mechanism. Reason: CCT is an ATP-dependent folding machine and the InterPro/PANTHER family supports the conserved chaperonin ATPase fold. |
| GO:0051082 unfolded protein binding | IEA GO_REF:0000120 | MODIFY | Summary: InterPro2GO still emits obsolete GO:0051082; the CCT/TRiC complex-level replacement is ATP-dependent protein folding chaperone activity. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct4, the evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct4 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Proposed replacements: ATP-dependent protein folding chaperone |
| GO:0140662 ATP-dependent protein folding chaperone | IEA GO_REF:0000002 | ACCEPT | Summary: ATP-dependent protein folding chaperone is the best available MF term for CCT4-containing CCT/TRiC. Reason: CCT/TRiC is an ATP-dependent folding machine, and CCT4 contributes as one subunit of this complex. Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine. |
| GO:0005515 protein binding | IPI PMID:16554755 Global landscape of protein complexes in the yeast Saccharom... | REMOVE | Summary: The large-scale complex map is useful CCT/TRiC context but does not define a specific Cct4 binding activity. Reason: This large-scale affinity-purification map is useful evidence for CCT/TRiC complex membership, but it does not define a specific molecular binding activity for Cct4 beyond the established chaperonin complex and ATP-dependent folding function. |
| GO:0005515 protein binding | IPI PMID:19536198 An atlas of chaperone-protein interactions in Saccharomyces ... | REMOVE | Summary: The TAP-tag chaperone atlas supports chaperonin contacts but GO:0005515 is not an informative Cct4 molecular-function assertion. Reason: PMID:19536198 reports broad TAP-tag chaperone interactions that are often indirect; the specific function is CCT/TRiC chaperonin activity. Supporting Evidence: PMID:19536198 The interactions presented are indirect TAP-tag based interactions and not direct binary interactions. |
| GO:0005515 protein binding | IPI PMID:27107014 An inter-species protein-protein interaction network across ... | REMOVE | Summary: The inter-species interactome does not identify a physiological Cct4 binding activity beyond CCT/TRiC folding. Reason: This inter-species interactome experiment tested biophysical yeast-human contacts at proteome scale; it does not identify a physiological Cct4 binding activity beyond the already curated chaperonin complex and ATP-dependent folding function. |
| GO:0005515 protein binding | IPI PMID:37968396 The social and structural architecture of the yeast protein ... | REMOVE | Summary: The proteome-scale interactome recovers CCT/TRiC connectivity but not a specific standalone protein-binding function for Cct4. Reason: This proteome-scale interactome helps recover CCT/TRiC connectivity, but it does not establish a specific protein-binding molecular function beyond Cct4's core ATP-dependent chaperonin activity. |
| GO:0006457 protein folding | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | ACCEPT | Summary: Direct biochemical evidence supports CCT-mediated protein folding. Reason: Yeast CCT purified through an internal tag catalyzes actin folding in vitro; because CCT4 is a required complex subunit, the process annotation is retained. Supporting Evidence: PMID:16762366 Yeast CCT catalyses the folding of yeast ACT1p and human beta-actin with nearly identical rate constants and yields. |
| GO:0005832 chaperonin-containing T-complex | IPI PMID:15704212 Physiological effects of unassembled chaperonin Cct subunits... | ACCEPT | Summary: Protein-interaction evidence supports CCT4 as part of the CCT complex. Reason: The study describes the CCT complex as two rings containing the Cct1p-Cct8p subunits, consistent with CCT4 complex membership. |
| GO:0005832 chaperonin-containing T-complex | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | ACCEPT | Summary: Direct analysis of purified yeast CCT supports CCT4 complex membership. Reason: The IDA evidence derives from purified yeast CCT; the cellular component term is accurate for the assembled complex. |
| GO:0051082 unfolded protein binding | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | MODIFY | Summary: Purified yeast CCT supports CCT/TRiC foldase function, not a standalone obsolete unfolded-protein-binding activity for Cct4. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct4, the actin-folding evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct4 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Proposed replacements: ATP-dependent protein folding chaperone |
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Download this section (compressed HTML)Q: Are there CCT4-specific substrate preferences within yeast CCT/TRiC that are separable from the activity of the assembled complex?
Experiment: Compare substrate folding outcomes after CCT4-specific conditional depletion against depletion of other CCT subunits to identify any subunit-biased substrate effects.
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Download this section (compressed HTML)Subunit of the cytosolic chaperonin Cct ring complex; related to Tcp1p, required for the assembly of actin and tubulins in vivo
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