Seroatlas · Human Serome Atlas

PCP2

Purkinje cell protein 2 homolog

Also known as: GPSM4, MGC41903, PCP2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q8IVA1
Gene: PCP2
Ensembl: ENSG00000174788
Chromosome: 19
Canonical length: 136 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nuclear speckles,Vesicles

OverviewNCBI Gene

Predicted to enable guanyl-nucleotide exchange factor activity. Predicted to act upstream of or within G protein-coupled opsin signaling pathway. Predicted to be located in neuronal cell body. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

136 residues, UniProt reviewed canonical sequence.

>Q8IVA1|PCP2
     1  MMDQEEKTEE GSGPCAEAGS PDQEGFFNLL SHVQGDRMEG QRCSLQAGPG QTTKSQSDPT
    61  PEMDSLMDML ASTQGRRMDD QRVTVSSLPG FQPVGSKDGA QKRAGTLSPQ PLLTPQDPTA
   121  LGFRRNSSPQ PPTQAP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PCP2 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: Unknown
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.62
Highest tissue expression: 111 nTPM

Expression across tissuesHPA

Tissue

cerebellum: 111 nTPM
testis: 111 nTPM
retina: 31 nTPM
salivary gland: 15 nTPM
kidney: 9.4 nTPM
skin: 6.6 nTPM

Single-cell type

late spermatids: 6,838 nCPM
early spermatids: 1,039 nCPM
retinal bipolar cells: 394 nCPM
platelets: 208 nCPM
late primary spermatocytes: 128 nCPM
epididymal efferent duct absorptive cells: 24 nCPM

Immune cell

total PBMC: 1.7 nTPM
neutrophil: 0.9 nTPM
plasmacytoid DC: 0.6 nTPM
MAIT T-cell: 0.4 nTPM
gdT-cell: 0.3 nTPM
naive B-cell: 0.3 nTPM

Brain region

cerebellum: 115 nTPM
white matter: 37 nTPM
pons: 14 nTPM
cerebral cortex: 7.8 nTPM
basal ganglia: 4.3 nTPM
medulla oblongata: 3.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PCP2.

Disease | ImmuneIEDB

Conditions an epitope on PCP2 was assayed in.

human immunodeficiency virus infectious disease T cell

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): 1.7
gnomAD pLI: 0
gnomAD missense Z: 0.17
DepMap mean gene effect: -0.07
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

G protein-coupled opsin signaling pathway

Molecular functions

guanyl-nucleotide exchange factor activity

Protein domainsUniProt · Pfam · InterPro

GoLoco motif
Tetratricopeptide-like helical domain superfamily
GoLoco motif
Purkinje cell protein 2

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PCP2 as an antibody target. Whether an autoantibody or antibody against PCP2 could matter depends on whether native PCP2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PCP2 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 PCP2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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