Seroatlas · Human Serome Atlas

PCP4

Calmodulin regulator protein PCP4

Also known as: PCP4_HUMAN, PEP-19

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

Protein identityUniProt · HPA

UniProt accession: P48539
Gene: PCP4
Ensembl: ENSG00000183036
Chromosome: 21
Canonical length: 62 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nucleoli fibrillar center

OverviewNCBI Gene

Enables calcium ion binding activity and calmodulin binding activity. Involved in positive regulation of CAMKK-AMPK signaling cascade and positive regulation of neuron differentiation. Located in cytosol and nucleus. Part of protein-containing complex. Biomarker of Huntington's disease and leiomyoma. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

62 residues, UniProt reviewed canonical sequence.

>P48539|PCP4
     1  MSERQGAGAT NGKDKTSGEN DGQKKVQEEF DIDMDAPETE RAAVAIQSQF RKFQKKKAGS
    61  QS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PCP4 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): 0.63
Highest tissue expression: 2,169 nTPM

Expression across tissuesHPA

Tissue

basal ganglia: 2,169 nTPM
choroid plexus: 1,407 nTPM
seminal vesicle: 1,202 nTPM
urinary bladder: 684 nTPM
prostate: 407 nTPM
retina: 357 nTPM

Single-cell type

retinal pigment epithelial cells: 2,157 nCPM
smooth muscle cells: 1,762 nCPM
retinal horizontal cells: 1,034 nCPM
epididymal efferent duct ciliated cells: 648 nCPM
epididymal principal cells: 611 nCPM
epididymal efferent duct absorptive cells: 455 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

basal ganglia: 1,305 nTPM
choroid plexus: 1,053 nTPM
thalamus: 990 nTPM
midbrain: 587 nTPM
amygdala: 369 nTPM
hypothalamus: 328 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): 1.77
gnomAD pLI: 0
gnomAD missense Z: 0.61
DepMap mean gene effect: 0.08
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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

Calmodulin Regulator PCP4-like

KeywordsUniProt

Calmodulin-binding

InteractionsUniProt · HPA

Protein binding partners of PCP4 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 PCP4 as an antibody target. Whether an autoantibody or antibody against PCP4 could matter depends on whether native PCP4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PCP4 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 PCP4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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