Seroatlas · Human Serome Atlas

CKAP4

Cytoskeleton-associated protein 4

Also known as: CKAP4_HUMAN, CLIMP-63, ERGIC-63, P63

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

Protein identityUniProt · HPA

UniProt accession: Q07065
Gene: CKAP4
Ensembl: ENSG00000136026
Chromosome: 12
Canonical length: 602 aa
Protein class: Predicted intracellular proteins, Predicted membrane proteins, Transporters
Subcellular location: Nuclear speckles,Endoplasmic reticulum,Mitochondria

OverviewNCBI Gene

Enables RNA binding activity. Located in several cellular components, including lipid droplet; nuclear speck; and rough endoplasmic reticulum. Biomarker of hepatocellular carcinoma. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

602 residues, UniProt reviewed canonical sequence.

>Q07065|CKAP4
     1  MPSAKQRGSK GGHGAASPSE KGAHPSGGAD DVAKKPPPAP QQPPPPPAPH PQQHPQQHPQ
    61  NQAHGKGGHR GGGGGGGKSS SSSSASAAAA AAAASSSASC SRRLGRALNF LFYLALVAAA
   121  AFSGWCVHHV LEEVQQVRRS HQDFSRQREE LGQGLQGVEQ KVQSLQATFG TFESILRSSQ
   181  HKQDLTEKAV KQGESEVSRI SEVLQKLQNE ILKDLSDGIH VVKDARERDF TSLENTVEER
   241  LTELTKSIND NIAIFTEVQK RSQKEINDMK AKVASLEESE GNKQDLKALK EAVKEIQTSA
   301  KSREWDMEAL RSTLQTMESD IYTEVRELVS LKQEQQAFKE AADTERLALQ ALTEKLLRSE
   361  ESVSRLPEEI RRLEEELRQL KSDSHGPKED GGFRHSEAFE ALQQKSQGLD SRLQHVEDGV
   421  LSMQVASARQ TESLESLLSK SQEHEQRLAA LQGRLEGLGS SEADQDGLAS TVRSLGETQL
   481  VLYGDVEELK RSVGELPSTV ESLQKVQEQV HTLLSQDQAQ AARLPPQDFL DRLSSLDNLK
   541  ASVSQVEADL KMLRTAVDSL VAYSVKIETN ENNLESAKGL LDDLRNDLDR LFVKVEKIHE
   601  KV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CKAP4 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: Cell surface
Secreted: No
Transmembrane segments: 1
Mean surface accessibility (rSASA): 0.54
Highest tissue expression: 95 nTPM

Expression across tissuesHPA

Tissue

bone marrow: 95 nTPM
esophagus: 68 nTPM
epididymis: 56 nTPM
salivary gland: 55 nTPM
stomach: 49 nTPM
placenta: 49 nTPM

Single-cell type

neutrophils: 656 nCPM
neutrophil progenitors: 551 nCPM
esophageal apical cells: 319 nCPM
cardiomyocytes: 301 nCPM
endometrial glandular cells: 227 nCPM
goblet cells: 183 nCPM

Immune cell

basophil: 107 nTPM
neutrophil: 30 nTPM
eosinophil: 23 nTPM
classical monocyte: 19 nTPM
non-classical monocyte: 11 nTPM
memory B-cell: 9.5 nTPM

Brain region

choroid plexus: 53 nTPM
thalamus: 36 nTPM
medulla oblongata: 32 nTPM
white matter: 31 nTPM
hypothalamus: 31 nTPM
pons: 31 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): 0.52
gnomAD pLI: 0.51
gnomAD missense Z: 0.85
DepMap mean gene effect: -0.02
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Molecular functions

RNA binding

Cellular components

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CKAP4 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 CKAP4 as an antibody target. Whether an autoantibody or antibody against CKAP4 could matter depends on whether native CKAP4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CKAP4 is annotated at the cell surface, where native CKAP4 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label CKAP4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...