PI15
Peptidase inhibitor 15
Also known as: P25TI, PI15_HUMAN
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- O43692
- Gene
- PI15
- Ensembl
- ENSG00000137558
- Chromosome
- 8
- Canonical length
- 258 aa
- Protein class
- Predicted secreted proteins
- Subcellular location
- Vesicles,Cytosol
- Secretome location
- Secreted in other tissues
OverviewNCBI Gene
This gene encodes a trypsin inhibitor. The protein shares similarity to insect venom allergens, mammalian testis-specific proteins and plant pathogenesis-related proteins. It is frequently expressed in human neuroblastoma and glioblastoma cell lines, and thus may play a role in the central nervous system. [provided by RefSeq, Jul 2008]
Canonical amino-acid sequenceUniProt
258 residues, UniProt reviewed canonical sequence.
>O43692|PI15
1 MIAISAVSSA LLFSLLCEAS TVVLLNSTDS SPPTNNFTDI EAALKAQLDS ADIPKARRKR
61 YISQNDMIAI LDYHNQVRGK VFPPAANMEY MVWDENLAKS AEAWAATCIW DHGPSYLLRF
121 LGQNLSVRTG RYRSILQLVK PWYDEVKDYA FPYPQDCNPR CPMRCFGPMC THYTQMVWAT
181 SNRIGCAIHT CQNMNVWGSV WRRAVYLVCN YAPKGNWIGE APYKVGVPCS SCPPSYGGSC
241 TDNLCFPGVT SNYLYWFKLocalizationUniProt · AlphaFold · HPA
Whether an antibody against PI15 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
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.38
- Highest tissue expression
- 51 nTPM
Expression across tissuesHPA
Tissue
- appendix: 51 nTPM
- smooth muscle: 47 nTPM
- prostate: 29 nTPM
- breast: 21 nTPM
- fallopian tube: 19 nTPM
- endometrium: 19 nTPM
Single-cell type
- basal prostatic cells: 187 nCPM
- breast hormone-responsive cells: 158 nCPM
- prostatic glandular cells: 105 nCPM
- smooth muscle cells: 85 nCPM
- prostatic club cells: 57 nCPM
- pericytes: 33 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
- thalamus: 6.9 nTPM
- cerebral cortex: 5 nTPM
- spinal cord: 3.4 nTPM
- midbrain: 3.1 nTPM
- hypothalamus: 3 nTPM
- medulla oblongata: 2.9 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)
- 0.79
- gnomAD pLI
- 0.02
- gnomAD missense Z
- 1
- DepMap mean gene effect
- 0.02
- DepMap dependency class
- selective
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
Molecular functions
Cellular components
Protein domainsUniProt · Pfam · InterPro
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads PI15 as an antibody target. Whether an autoantibody or antibody against PI15 could matter depends on whether native PI15 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
PI15 is annotated as secreted, so native PI15 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label PI15 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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