ALPK1

UniProt ID: Q96QP1
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

ALPK1 is a cytosolic alpha-family protein kinase that couples recognition of microbial nucleotide-heptoses to innate immune signaling. Its N-terminal ligand-binding domain recognizes ADP-heptose, activating the C-terminal kinase to phosphorylate TIFA, prominently at Thr9. Phosphorylated TIFA oligomerizes and recruits downstream ubiquitin-ligase and kinase machinery that activates NF-ΞΊB and inflammatory gene expression. ALPK1 also occurs at centrosomes, mitotic spindle poles and ciliary bases in tested human cells; patient-cell ciliation abnormalities are documented, while the local biochemical mechanism remains less resolved. Disease-associated variants can increase signaling and broaden responsiveness to endogenous nucleotide sugars, helping explain ROSAH syndrome and selected adnexal tumors.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0000922 spindle pole
IDA
PMID:30967659
ALPK1 missense pathogenic variant in five families leads to ...
KEEP AS NON CORE
Summary: ALPK1 is detected at mitotic spindle poles in human retinal pigment epithelial cells.
Reason: PMID:30967659 Figure 4a–f shows endogenous ALPK1 immunostaining at spindle poles in ARPE19 cells, with tubulin costaining. This is a supported cell-cycle-associated pool; the study does not identify the local ALPK1 substrate or establish spindle assembly as its principal molecular role.
Supporting Evidence:
PMID:30967659
localization of ALPK1 in the spindle poles at metaphase
GO:0000922 spindle pole
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: ALPK1 is detected at mitotic spindle poles in human retinal pigment epithelial cells.
Reason: PMID:30967659 Figure 4a–f shows endogenous ALPK1 immunostaining at spindle poles in ARPE19 cells, with tubulin costaining. This is a supported cell-cycle-associated pool; the study does not identify the local ALPK1 substrate or establish spindle assembly as its principal molecular role.
Propagation Review
Root cause: NO FAILURE NON CORE
Sources checked:
UniProtKB-SubCell:SL-0448 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
PMID:30967659
localization of ALPK1 in the spindle poles at metaphase
GO:0002753 cytoplasmic pattern recognition receptor signaling pathway
IBA
GO_REF:0000033
ACCEPT
Summary: ALPK1 initiates cytosolic bacterial nucleotide-heptose sensing through TIFA.
Reason: The seeded PAINT node represents inherited intracellular microbial sensing. Human ALPK1 directly recognizes ADP-heptose and phosphorylates TIFA; mouse Alpk1-dependent inflammation is complementary organismal evidence. Target self-evidence in the descendant list is legitimate experimental grounding. No target-specific loss of this pathway role is evident.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
PANTHER:PTN002928819 SUPPORTS TRANSFER
This is the ancestral PAINT node supplied by the seed. Human target experiments support the inherited kinase/innate-sensing biology; target self-evidence is legitimate descendant support. The local family metadata identifies PTHR46747, but no cached PAINT tree/IBD file was available to independently reconstruct node placement.
Supporting Evidence:
PMID:28222186
TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0002753 cytoplasmic pattern recognition receptor signaling pathway
IDA
PMID:28222186
ALPK1 controls TIFA/TRAF6-dependent innate immunity against ...
ACCEPT
Summary: ALPK1 initiates cytosolic bacterial nucleotide-heptose sensing through TIFA.
Reason: The full human-cell study places ALPK1 upstream of TIFA oligomerization and TRAF6/NF-ΞΊB activation: siRNA-resistant full-length ALPK1 rescues the phenotype, whereas the kinase-domain deletion does not. The original HBP interpretation is refined by the later ADP-heptose chemistry; the positive signaling experiments remain valid.
Supporting Evidence:
PMID:28222186
TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0002753 cytoplasmic pattern recognition receptor signaling pathway
IDA
PMID:28877472
ALPK1- and TIFA-Dependent Innate Immune Response Triggered b...
ACCEPT
Summary: ALPK1 initiates cytosolic bacterial nucleotide-heptose sensing through TIFA.
Reason: The abstract reports ALPK1-dependent TIFA phosphorylation, TIFAsome formation and NF-ΞΊB activation during H. pylori infection. These positive experiments agree with the independently established ALPK1–TIFA pathway. The local source is abstract-only, so detailed construct and assay scope is not inferred; the later ADP-heptose identification refines the original HBP model.
Supporting Evidence:
PMID:28877472
NF-ΞΊB activation, TIFA phosphorylation, and TIFAsome formation depend on a functional ALPK1 kinase
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0002753 cytoplasmic pattern recognition receptor signaling pathway
IDA
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: ALPK1 initiates cytosolic bacterial nucleotide-heptose sensing through TIFA.
Reason: The 2018 study combines receptor loss/rescue, direct ADP-heptose binding and TIFA phosphorylation. ALPK1 performs both recognition and the initiating kinase step, establishing process participation beyond genetic necessity. Human-cell biochemical work is distinct from the mouse inflammatory experiments.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0002753 cytoplasmic pattern recognition receptor signaling pathway
TAS
Reactome:R-HSA-9645460
ACCEPT
Summary: ALPK1 initiates cytosolic bacterial nucleotide-heptose sensing through TIFA.
Reason: The curated human pathway explicitly places ALPK1 at cytosolic ligand recognition and TIFA phosphorylation before TRAF6/TAK1/IKK activation. This is direct participation in the receptor-signaling pathway, not attribution of the downstream partners’ ubiquitin-ligase or kinase reactions to ALPK1.
Supporting Evidence:
Reactome:R-HSA-9645460
This Reactome module describes ALPK1 as a cytosolic innate immune receptor for bacterial ADP-heptose.
GO:0004674 protein serine/threonine kinase activity
EXP
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: ALPK1 is an ADP-heptose-activated protein serine/threonine kinase.
Reason: Direct TIFA phosphorylation and kinase-inactive rescue controls support the broad serine/threonine-kinase class. The source-resolved TIFA site is Thr9. GO:0004674 includes threonine-specific kinase synonyms and threonine-directed activities, supporting retention of this conventional broad classification while the separate serine-specific assertions remain unresolved. The EXP and IDA source assertions are preserved separately.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:37072480
Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH
GO:0004674 protein serine/threonine kinase activity
IBA
GO_REF:0000033
ACCEPT
Summary: ALPK1 is an ADP-heptose-activated protein serine/threonine kinase.
Reason: Direct TIFA phosphorylation and kinase-inactive rescue controls support the broad serine/threonine-kinase class. The source-resolved TIFA site is Thr9. GO:0004674 includes threonine-specific kinase synonyms and threonine-directed activities, supporting retention of this conventional broad classification while the separate serine-specific assertions remain unresolved. The PAINT inference is consistent with target experimental evidence.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
PANTHER:PTN002928819 SUPPORTS TRANSFER
This is the ancestral PAINT node supplied by the seed. Human target experiments support the inherited kinase/innate-sensing biology; target self-evidence is legitimate descendant support. The local family metadata identifies PTHR46747, but no cached PAINT tree/IBD file was available to independently reconstruct node placement.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:37072480
Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH
GO:0004674 protein serine/threonine kinase activity
IDA
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: ALPK1 is an ADP-heptose-activated protein serine/threonine kinase.
Reason: Direct TIFA phosphorylation and kinase-inactive rescue controls support the broad serine/threonine-kinase class. The source-resolved TIFA site is Thr9. GO:0004674 includes threonine-specific kinase synonyms and threonine-directed activities, supporting retention of this conventional broad classification while the separate serine-specific assertions remain unresolved. The EXP and IDA source assertions are preserved separately.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:37072480
Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH
GO:0004674 protein serine/threonine kinase activity
IEA
GO_REF:0000120
ACCEPT
Summary: ALPK1 is an ADP-heptose-activated protein serine/threonine kinase.
Reason: Direct TIFA phosphorylation and kinase-inactive rescue controls support the broad serine/threonine-kinase class. The source-resolved TIFA site is Thr9. GO:0004674 includes threonine-specific kinase synonyms and threonine-directed activities, supporting retention of this conventional broad classification while the separate serine-specific assertions remain unresolved. The alpha-kinase domains and EC mapping agree with the demonstrated human enzyme activity.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
InterPro:IPR004166 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
InterPro:IPR043529 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
EC:2.7.11.1 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:37072480
Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH
GO:0005515 protein binding
IPI
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
REMOVE
Summary: The ALPK1–TIFA interaction is part of the established kinase–substrate mechanism.
Reason: The source supports an ADP-heptose-dependent ALPK1–TIFA association and phosphorylation. Generic protein binding adds no informative molecular function beyond the already present kinase annotations from this same study. Remove the generic assertion without denying the interaction or adding a duplicate kinase replacement.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
Reactome:R-HSA-9645524
ADP-heptose stimulated coimmunoprecipitation of TIFA with ALPK1 and TRAF6
GO:0005515 protein binding
IPI
PMID:36931259
A central chaperone-like role for 14-3-3 proteins in human c...
UNDECIDED
Summary: The specific ALPK1–14-3-3 epsilon assay remains unverified.
Reason: The paper maps human 14-3-3 interactomes, and the seeded IPI row identifies P62258 as the partner. The local abstract and retrieved PubMed record do not expose the ALPK1-specific result or supplemental target assay. The generic-binding default does not justify inventing a client-regulatory function or rejecting an uninspected curated interaction; retain uncertainty pending the actual target evidence.
Supporting Evidence:
PMID:36931259
we map the interactomes of all human 14-3-3 paralogs
GO:0005524 ATP binding
IEA
GO_REF:0000002
ACCEPT
Summary: ATP binding supports the ALPK1 kinase reaction.
Reason: InterPro maps the alpha-kinase domain to ATP binding. Human ALPK1 uses ATP to phosphorylate substrate; this cofactor interaction is intrinsic to the core catalytic mechanism, rather than a separate signaling activity.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
InterPro:IPR004166 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
file:human/ALPK1/ALPK1-uniprot.txt
L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein]
GO:0005813 centrosome
IDA
GO_REF:0000052
KEEP AS NON CORE
Summary: ALPK1 has a supported centrosomal pool.
Reason: Human Protein Atlas HPA027435 immunofluorescence supports centrosomal localization in A-431, U-251MG and ASC52telo cells; lack of staining in other tested lines is recorded separately and is not universal exclusion. The independent ARPE19 study corroborates this specialized pool.
Supporting Evidence:
PMID:30967659
in centrosomes of cells during interphase
GO:0005813 centrosome
IDA
PMID:30967659
ALPK1 missense pathogenic variant in five families leads to ...
KEEP AS NON CORE
Summary: ALPK1 has a supported centrosomal pool.
Reason: The full primary Figure 4d–i shows ALPK1 colocalization with gamma-tubulin at centrosomes in human ARPE19 cells during mitosis and interphase. Retain this contextual compartment without inferring a centrosome-specific kinase substrate.
Supporting Evidence:
PMID:30967659
in centrosomes of cells during interphase
GO:0005813 centrosome
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: ALPK1 has a supported centrosomal pool.
Reason: The full primary Figure 4d–i shows ALPK1 colocalization with gamma-tubulin at centrosomes in human ARPE19 cells during mitosis and interphase. Retain this contextual compartment without inferring a centrosome-specific kinase substrate.
Propagation Review
Root cause: NO FAILURE NON CORE
Sources checked:
UniProtKB-SubCell:SL-0048 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
PMID:30967659
in centrosomes of cells during interphase
GO:0005829 cytosol
IDA
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: Cytosol is the principal compartment of ALPK1 innate immune sensing.
Reason: The receptor recognizes nucleotide-heptose in the cytosol and phosphorylates TIFA there. The 2018 localization experiment and independent ARPE19 diffuse cytosolic staining support this location alongside the separately documented centrosomal pool.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
IEA
GO_REF:0000044
ACCEPT
Summary: Cytosol is the principal compartment of ALPK1 innate immune sensing.
Reason: The receptor recognizes nucleotide-heptose in the cytosol and phosphorylates TIFA there. The 2018 localization experiment and independent ARPE19 diffuse cytosolic staining support this location alongside the separately documented centrosomal pool.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
UniProtKB-SubCell:SL-0091 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645394
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TRAF6 synthesis of free K63-linked ubiquitin chains. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645406
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TAB2/TAB3–TAK1 recruitment to the ubiquitin-bearing signaling assembly. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645414
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TRAF6 autoubiquitination. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645428
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes direct binding of ADP-heptose to ALPK1. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645442
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TAK1 autophosphorylation within the downstream signaling assembly. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645481
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TIFA oligomerization following Thr9 phosphorylation. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645501
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TRAF6 oligomerization downstream of TIFA. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645520
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TIFA-dependent recruitment of TRAF6. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645524
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes ADP-heptose-dependent association of ALPK1 and TIFA. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9645535
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes ALPK1-catalyzed TIFA Thr9 phosphorylation. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
GO:0005829 cytosol
TAS
Reactome:R-HSA-9758604
ACCEPT
Summary: The curated signaling event places ALPK1 in its cytosolic pathway context.
Reason: This human Reactome event describes TRAF6-dependent IKBKG ubiquitination. The GO assertion is cytosolic location, consistent with the ALPK1 receptor/kinase pool and source pathway model. It does not assign the event’s partner chemistry to ALPK1; the direct ALPK1 reaction is ligand-triggered TIFA phosphorylation.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:30967659
shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: ALPK1 is detected at the base of primary cilia.
Reason: Human ARPE19 microscopy in PMID:30967659 Figure 4j–l localizes ALPK1 at the ciliary base after serum starvation. HPA also reports ciliary basal-body staining in ASC52telo cells. Retain the original source resolution; the mouse photoreceptor connecting-cilium result is not relabeled as a human retinal experiment. This specialized pool is distinct from the established cytosolic innate-receptor mechanism.
Propagation Review
Root cause: NO FAILURE NON CORE
Sources checked:
PANTHER:PTN002928819 SUPPORTS TRANSFER
This is the ancestral PAINT node supplied by the seed. Human target experiments support the inherited ciliary localization, retained as a contextual pool.
Supporting Evidence:
PMID:30967659
Super-resolution confocal imaging showed the presence of ALPK1 in the base of primary cilia
IDA
PMID:30967659
ALPK1 missense pathogenic variant in five families leads to ...
KEEP AS NON CORE
Summary: ALPK1 is detected at the base of primary cilia.
Reason: Human ARPE19 microscopy in PMID:30967659 Figure 4j–l localizes ALPK1 at the ciliary base after serum starvation. HPA also reports ciliary basal-body staining in ASC52telo cells. Retain the original source resolution; the mouse photoreceptor connecting-cilium result is not relabeled as a human retinal experiment. This specialized pool is distinct from the established cytosolic innate-receptor mechanism.
Supporting Evidence:
PMID:30967659
Super-resolution confocal imaging showed the presence of ALPK1 in the base of primary cilia
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: ALPK1 is detected at the base of primary cilia.
Reason: Human ARPE19 microscopy in PMID:30967659 Figure 4j–l localizes ALPK1 at the ciliary base after serum starvation. HPA also reports ciliary basal-body staining in ASC52telo cells. Retain the original source resolution; the mouse photoreceptor connecting-cilium result is not relabeled as a human retinal experiment. This specialized pool is distinct from the established cytosolic innate-receptor mechanism.
Propagation Review
Root cause: NO FAILURE NON CORE
Sources checked:
UniProtKB-SubCell:SL-0066 SUPPORTS TRANSFER
The seeded mapping source is preserved. Its domain, location or enzyme-class assertion agrees with the target-level source evidence discussed in the reason.
Supporting Evidence:
PMID:30967659
Super-resolution confocal imaging showed the presence of ALPK1 in the base of primary cilia
GO:0036064 ciliary basal body
IDA
GO_REF:0000052
KEEP AS NON CORE
Summary: ALPK1 is detected at the base of primary cilia.
Reason: Human ARPE19 microscopy in PMID:30967659 Figure 4j–l localizes ALPK1 at the ciliary base after serum starvation. HPA also reports ciliary basal-body staining in ASC52telo cells. Retain the original source resolution; the mouse photoreceptor connecting-cilium result is not relabeled as a human retinal experiment. This specialized pool is distinct from the established cytosolic innate-receptor mechanism.
Supporting Evidence:
PMID:30967659
Super-resolution confocal imaging showed the presence of ALPK1 in the base of primary cilia
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IDA
PMID:28222186
ALPK1 controls TIFA/TRAF6-dependent innate immunity against ...
ACCEPT
Summary: ALPK1 positively regulates canonical NF-ΞΊB signaling through TIFA.
Reason: ALPK1 kinase activity promotes TIFA phosphorylation/oligomerization and downstream TRAF6–TAK1–IKK signaling. The full human-cell experiments show ALPK1 depletion blocks infection-induced IΞΊBΞ± degradation and p65 nuclear translocation, with kinase-domain-dependent rescue of TIFA oligomers. This is pathway-specific activation, not a claim that ALPK1 directly phosphorylates IKK or is required for all TNF/IL-1 signaling.
Supporting Evidence:
PMID:28222186
TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IDA
PMID:28877472
ALPK1- and TIFA-Dependent Innate Immune Response Triggered b...
ACCEPT
Summary: ALPK1 positively regulates canonical NF-ΞΊB signaling through TIFA.
Reason: ALPK1 kinase activity promotes TIFA phosphorylation/oligomerization and downstream TRAF6–TAK1–IKK signaling. The source’s positive ALPK1-dependent TIFA and NF-ΞΊB findings agree with this established mechanism. This is pathway-specific activation, not a claim that ALPK1 directly phosphorylates IKK or is required for all TNF/IL-1 signaling.
Supporting Evidence:
PMID:28877472
NF-ΞΊB activation, TIFA phosphorylation, and TIFAsome formation depend on a functional ALPK1 kinase
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IDA
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: ALPK1 positively regulates canonical NF-ΞΊB signaling through TIFA.
Reason: ALPK1 kinase activity promotes TIFA phosphorylation/oligomerization and downstream TRAF6–TAK1–IKK signaling. The source’s positive ALPK1-dependent TIFA and NF-ΞΊB findings agree with this established mechanism. This is pathway-specific activation, not a claim that ALPK1 directly phosphorylates IKK or is required for all TNF/IL-1 signaling.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0045087 innate immune response
IBA
GO_REF:0000033
ACCEPT
Summary: Microbial nucleotide-heptose recognition is an innate immune function of ALPK1.
Reason: Ligand recognition and direct phosphorylation of the signaling adaptor constitute actual work in the innate response. Retain this valid broader core process alongside the more specific receptor-signaling annotation. Human cellular experiments and mouse inflammatory phenotypes are distinguished; disease-associated activation does not replace the wild-type mechanism.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
PANTHER:PTN002928819 SUPPORTS TRANSFER
This is the ancestral PAINT node supplied by the seed. Human target experiments support the inherited kinase/innate-sensing biology; target self-evidence is legitimate descendant support. The local family metadata identifies PTHR46747, but no cached PAINT tree/IBD file was available to independently reconstruct node placement.
Supporting Evidence:
PMID:28222186
TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0045087 innate immune response
IDA
PMID:28222186
ALPK1 controls TIFA/TRAF6-dependent innate immunity against ...
ACCEPT
Summary: Microbial nucleotide-heptose recognition is an innate immune function of ALPK1.
Reason: Ligand recognition and direct phosphorylation of the signaling adaptor constitute actual work in the innate response. Retain this valid broader core process alongside the more specific receptor-signaling annotation. Human cellular experiments and mouse inflammatory phenotypes are distinguished; disease-associated activation does not replace the wild-type mechanism.
Supporting Evidence:
PMID:28222186
TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0045087 innate immune response
IDA
PMID:28877472
ALPK1- and TIFA-Dependent Innate Immune Response Triggered b...
ACCEPT
Summary: Microbial nucleotide-heptose recognition is an innate immune function of ALPK1.
Reason: Ligand recognition and direct phosphorylation of the signaling adaptor constitute actual work in the innate response. Retain this valid broader core process alongside the more specific receptor-signaling annotation. Human cellular experiments and mouse inflammatory phenotypes are distinguished; disease-associated activation does not replace the wild-type mechanism.
Supporting Evidence:
PMID:28877472
NF-ΞΊB activation, TIFA phosphorylation, and TIFAsome formation depend on a functional ALPK1 kinase
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0045087 innate immune response
IDA
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
ACCEPT
Summary: Microbial nucleotide-heptose recognition is an innate immune function of ALPK1.
Reason: Ligand recognition and direct phosphorylation of the signaling adaptor constitute actual work in the innate response. Retain this valid broader core process alongside the more specific receptor-signaling annotation. Human cellular experiments and mouse inflammatory phenotypes are distinguished; disease-associated activation does not replace the wild-type mechanism.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0048029 monosaccharide binding
IBA
GO_REF:0000033
MODIFY
Summary: ALPK1 recognizes microbial ADP-heptose and initiates innate immune signaling.
Reason: The intact ADP-heptose ligand is a nucleotide-sugar derivative, and binding stimulates ALPK1-dependent TIFA phosphorylation and innate signaling. Human N-terminal structural/binding evidence and wild-type versus kinase-inactive cellular rescue support pattern recognition receptor activity (GO:0038187), whose definition covers recognition of a microbial pattern that initiates an innate response. This functional refinement is more informative than carbohydrate derivative binding, an ancestor of the already retained ATP-binding annotation. It does not assert free-heptose binding, transfer partner signaling chemistry to ALPK1, or require a transmembrane receptor. The original IBA/IPI evidence and source entities are preserved.
Propagation Review
Root cause: TERM SCOPING PROBLEM
Failure modes: GRANULARITY MISMATCH
Sources checked:
PANTHER:PTN002928819 SUPPORTS TRANSFER
This is the ancestral PAINT node supplied by the seed. Human target experiments support the inherited nucleotide-heptose sensing activity. The target-level functional refinement uses direct ligand recognition coupled to signaling; it does not allege lineage loss, wrong node placement or circular target self-evidence.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0048029 monosaccharide binding
IPI
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
MODIFY
Summary: ALPK1 recognizes microbial ADP-heptose and initiates innate immune signaling.
Reason: The intact ADP-heptose ligand is a nucleotide-sugar derivative, and binding stimulates ALPK1-dependent TIFA phosphorylation and innate signaling. Human N-terminal structural/binding evidence and wild-type versus kinase-inactive cellular rescue support pattern recognition receptor activity (GO:0038187), whose definition covers recognition of a microbial pattern that initiates an innate response. This functional refinement is more informative than carbohydrate derivative binding, an ancestor of the already retained ATP-binding annotation. It does not assert free-heptose binding, transfer partner signaling chemistry to ALPK1, or require a transmembrane receptor. The original IBA/IPI evidence and source entities are preserved.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
GO:0060271 cilium assembly
IMP
PMID:30967659
ALPK1 missense pathogenic variant in five families leads to ...
UNDECIDED
Summary: A ROSAH-associated ALPK1 variant is associated with defective primary-cilium assembly.
Reason: The full source measures reduced ciliation in fibroblasts from two p.Thr237Met patients against one unaffected control after serum starvation, with three replicate experiments. Endogenous human ALPK1 localizes to the ciliary base, but localization and the patient phenotype do not resolve whether normal ALPK1 performs cilium-assembly work or whether altered signaling by the gain-of-function variant disrupts ciliogenesis. The HeLa wild-type/mutant overexpression comparison measures multinucleation rather than cilium assembly; no wild-type loss/rescue ciliation assay was identified in the inspected source. Preserve the positive mutant phenotype and curated IMP assertion, with an unresolved judgment about normal process participation. A dedicated ciliary enzyme or mapped substrate is not required in principle for such participation.
Supporting Evidence:
PMID:30967659
Affected family member fibroblasts demonstrated defective ciliogenesis.
PMID:30967659
Super-resolution confocal imaging showed the presence of ALPK1 in the base of primary cilia
GO:0106310 protein serine kinase activity
EXP
PMID:27169898
ALPK1 phosphorylates myosin IIA modulating TNF-Ξ± trafficking...
UNDECIDED
Summary: The myosin-IIA phosphorylation assay does not resolve a serine acceptor.
Reason: The full paper shows ATP- and ALPK1-dependent phosphorylation of phosphatase-treated, immunoprecipitated myosin IIA, with omission controls. Detection uses ProQ and pan-phospho-Ser/Thr rather than a mapped serine site. ALPK1 purified from human HEK293F also coeluted endogenous myosin, a limitation the authors acknowledge. This positive kinase evidence supports the broader existing activity, while the exact serine-specific source assertion remains unresolved; no claim is made that ALPK1 lacks serine kinase capacity.
Supporting Evidence:
PMID:27169898
The phosphorylation of myosin IIA was strongly seen after incubation with both ALPK1 and ATP on the Pro-Q staining assay
GO:0106310 protein serine kinase activity
EXP
PMID:30111836
Alpha-kinase 1 is a cytosolic innate immune receptor for bac...
UNDECIDED
Summary: The inspected TIFA evidence establishes threonine phosphorylation, while the serine-specific assertion remains unresolved.
Reason: The source abstract, original first-page preview and publisher Extended Data captions support ADP-heptose-dependent TIFA phosphorylation at Thr9. The complete original Methods and remaining main results were not recovered. The newer human-cell kinase study also identifies TIFA threonines, which is not proof that the original study never assayed a serine substrate. Retain uncertainty rather than reject the experimental curator’s narrower assertion from partial access.
Supporting Evidence:
PMID:30111836
ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
PMID:37072480
Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH
GO:0106310 protein serine kinase activity
IEA
GO_REF:0000116
UNDECIDED
Summary: The serine-specific Rhea mapping inherits an unresolved residue-class assertion.
Reason: RHEA:17989 correctly denotes phosphorylation of a protein serine residue, and the mapping itself is preserved. Its UniProt evidence points to the same two studies reviewed here: one pan-Ser/Thr myosin assay and one incompletely accessible TIFA study whose inspected site is Thr9. Those establish broad kinase activity but do not independently resolve the serine subactivity in this audit.
Propagation Review
Root cause: UNRESOLVED
Sources checked:
RHEA:17989 UNRESOLVED
The seeded mapping source is preserved. Rhea supplies the serine reaction; supporting residue-specific experiments remain unresolved, rather than the mapping being mechanically wrong.
Supporting Evidence:
file:human/ALPK1/ALPK1-uniprot.txt
L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein]

Core Functions

Cytosolic nucleotide-heptose sensing coupled to TIFA phosphorylation. Direct ADP-heptose recognition by the N-terminal domain activates the alpha-kinase domain, initiating TIFA-dependent innate signaling and canonical NF-ΞΊB activation. Thr9 is the well-resolved TIFA acceptor; the broad kinase class is used without asserting unresolved serine-specific chemistry. Downstream ubiquitination and TAK1/IKK catalysis belong to the partner enzymes.

Supporting Evidence:
  • PMID:30111836
    ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA.
  • PMID:28222186
    TIFA oligomerization was restored by overexpressing a siRNA-resistant full length ALPK1 construct.
  • PMID:30967659
    shows a diffuse cytosolic pattern and enrichment of ALPK1 in centrosomes of the cells
  • PMID:37072480
    Data confirmed that ALPK1 induced the phosphorylation of TIFA on T9 residues in response to the recognition of ADPH

References

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Suggested Questions for Experts

Q: Does normal ALPK1 participate in cilium assembly, or does altered signaling by ROSAH variants secondarily disrupt ciliogenesis, and which experiments distinguish these mechanisms?

Q: What site-resolved human experiment supports the seeded serine-specific kinase activity, separately from TIFA threonine phosphorylation and pan-Ser/Thr myosin assays?

Q: How does ALPK1 discriminate microbial nucleotide-heptoses from endogenous nucleotide sugars, and how do ROSAH variants alter this selectivity?

Q: Does ALPK1 binding to 14-3-3 epsilon regulate its localization, aggregation or kinase activity under physiological conditions?

πŸ“š Additional Documentation

Notes

(ALPK1-notes.md)

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