Seroatlas · Human Serome Atlas

AKAP4

A-kinase anchor protein 4

Also known as: AKAP4_HUMAN, AKAP82, CT99, Fsc1, hAKAP82, HI, p82

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q5JQC9
Gene
AKAP4
Ensembl
ENSG00000147081
Chromosome
X
Canonical length
854 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

The A-kinase anchor proteins (AKAPs) are a group of structurally diverse proteins, which have the common function of binding to the regulatory subunit of protein kinase A (PKA) and confining the holoenzyme to discrete locations within the cell. This gene encodes a member of the AKAP family. The encoded protein is localized to the sperm flagellum and may be involved in the regulation of sperm motility. Alternative splicing of this gene results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

854 residues, UniProt reviewed canonical sequence.

>Q5JQC9|AKAP4
     1  MMAYSDTTMM SDDIDWLRSH RGVCKVDLYN PEGQQDQDRK VICFVDVSTL NVEDKDYKDA
    61  ASSSSEGNLN LGSLEEKEII VIKDTEKKDQ SKTEGSVCLF KQAPSDPVSV LNWLLSDLQK
   121  YALGFQHALS PSTSTCKHKV GDTEGEYHRA SSENCYSVYA DQVNIDYLMN RPQNLRLEMT
   181  AAKNTNNNQS PSAPPAKPPS TQRAVISPDG ECSIDDLSFY VNRLSSLVIQ MAHKEIKEKL
   241  EGKSKCLHHS ICPSPGNKER ISPRTPASKI ASEMAYEAVE LTAAEMRGTG EESREGGQKS
   301  FLYSELSNKS KSGDKQMSQR ESKEFADSIS KGLMVYANQV ASDMMVSLMK TLKVHSSGKP
   361  IPASVVLKRV LLRHTKEIVS DLIDSCMKNL HNITGVLMTD SDFVSAVKRN LFNQWKQNAT
   421  DIMEAMLKRL VSALIGEEKE TKSQSLSYAS LKAGSHDPKC RNQSLEFSTM KAEMKERDKG
   481  KMKSDPCKSL TSAEKVGEHI LKEGLTIWNQ KQGNSCKVAT KACSNKDEKG EKINASTDSL
   541  AKDLIVSALK LIQYHLTQQT KGKDTCEEDC PGSTMGYMAQ STQYEKCGGG QSAKALSVKQ
   601  LESHRAPGPS TCQKENQHLD SQKMDMSNIV LMLIQKLLNE NPFKCEDPCE GENKCSEPRA
   661  SKAASMSNRS DKAEEQCQEH QELDCTSGMK QANGQFIDKL VESVMKLCLI MAKYSNDGAA
   721  LAELEEQAAS ANKPNFRGTR CIHSGAMPQN YQDSLGHEVI VNNQCSTNSL QKQLQAVLQW
   781  IAASQFNVPM LYFMGDKDGQ LEKLPQVSAK AAEKGYSVGG LLQEVMKFAK ERQPDEAVGK
   841  VARKQLLDWL LANL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AKAP4 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.53
Highest tissue expression
187 nTPM

Expression across tissuesHPA

Tissue

  • testis: 187 nTPM
  • breast: 0.1 nTPM
  • prostate: 0.1 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM
  • amygdala: 0 nTPM

Single-cell type

  • late spermatids: 4,307 nCPM
  • early spermatids: 918 nCPM
  • late primary spermatocytes: 145 nCPM
  • sertoli cells: 9.2 nCPM
  • leydig cells: 6.1 nCPM
  • undifferentiated spermatogonia: 3.8 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 nTPM
  • hippocampal formation: 0 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.25
gnomAD pLI
0.99
gnomAD missense Z
0.78
DepMap mean gene effect
0
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of AKAP4 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads AKAP4 as an antibody target. Whether an autoantibody or antibody against AKAP4 could matter depends on whether native AKAP4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

AKAP4 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label AKAP4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/AKAP4. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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