Seroatlas · Human Serome Atlas

PITPNB

Phosphatidylinositol transfer protein beta isoform

Also known as: PIPNB_HUMAN, VIB1B

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

Protein identityUniProt · HPA

UniProt accession: P48739
Gene: PITPNB
Ensembl: ENSG00000180957
Chromosome: 22
Canonical length: 271 aa
Protein class: Predicted intracellular proteins
Subcellular location: Vesicles,Cytosol

OverviewNCBI Gene

This gene encodes a cytoplasmic protein that catalyzes the transfer of phosphatidylinositol and phosphatidylcholine between membranes. This transfer activity is required for COPI complex-mediated retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Sep 2013]

Canonical amino-acid sequenceUniProt

271 residues, UniProt reviewed canonical sequence.

>P48739|PITPNB
     1  MVLIKEFRVV LPCSVQEYQV GQLYSVAEAS KNETGGGEGI EVLKNEPYEK DGEKGQYTHK
    61  IYHLKSKVPA FVRMIAPEGS LVFHEKAWNA YPYCRTIVTN EYMKDDFFIK IETWHKPDLG
   121  TLENVHGLDP NTWKTVEIVH IDIADRSQVE PADYKADEDP ALFQSVKTKR GPLGPNWKKE
   181  LANSPDCPQM CAYKLVTIKF KWWGLQSKVE NFIQKQEKRI FTNFHRQLFC WIDKWIDLTM
   241  EDIRRMEDET QKELETMRKR GSVRGTSAAD V

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PITPNB 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: Other membrane
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.26
Highest tissue expression: 78 nTPM

Expression across tissuesHPA

Tissue

blood vessel: 78 nTPM
liver: 53 nTPM
urinary bladder: 51 nTPM
colon: 50 nTPM
esophagus: 49 nTPM
placenta: 46 nTPM

Single-cell type

basal keratinocytes: 336 nCPM
suprabasal keratinocytes: 302 nCPM
ocular epithelial cells: 258 nCPM
urothelial cells: 241 nCPM
smooth muscle cells: 234 nCPM
endometrial glandular cells: 230 nCPM

Immune cell

T-reg: 41 nTPM
basophil: 36 nTPM
memory B-cell: 35 nTPM
MAIT T-cell: 34 nTPM
memory CD8 T-cell: 32 nTPM
gdT-cell: 31 nTPM

Brain region

thalamus: 56 nTPM
midbrain: 56 nTPM
cerebral cortex: 54 nTPM
hypothalamus: 53 nTPM
pons: 52 nTPM
cerebellum: 52 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): 0.29
gnomAD pLI: 0.98
gnomAD missense Z: 2.15
DepMap mean gene effect: -0.02
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% 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

Antibody and autoantibody relevanceSeroatlas analysis

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

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

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