PCSK1N

Members of the subtilisin-like proprotein convertase family process latent precursor proteins into their biologically active products. The protein encoded by this gene appears to function as an endogenous inhibitor of proprotein convertase subtilisin/kexin type 1. [provided by RefSeq]

proprotein convertase subtilisin/kexin type 1 inhibitor

May function in the control of the neuroendocrine secretory pathway. Proposed be a specific endogenous inhibitor of PCSK1. ProSAAS and Big PEN-LEN, both containing the C-terminal inhibitory domain, but not the further processed peptides reduce PCSK1 activity in the endoplasmic reticulum and Golgi. It reduces the activity of the 84 kDa form but not the autocatalytically derived 66 kDa form of PCSK1. Subsequent processing of proSAAS may eliminate the inhibition. Slows down convertase-mediated processing of proopiomelanocortin and proenkephalin. May control the intracellular timing of PCSK1 rather than its total level of activity (By similarity).
Big LEN
Endogenous ligand for GPR171. Neuropeptide involved in the regulation of feeding.
PEN
Endogenous ligand for GPR171. Neuropeptide involved in the regulation of feeding.

Neuropeptide signaling pathwayIEA:UniProtKB-KW
Peptide hormone processingIEA:Ensembl
Response to coldIEA:Ensembl
Response to dietary excessIEA:Ensembl

Secreted
Golgi apparatus, trans-Golgi network
A N-terminal processed peptide, probably Big SAAS or Little SAAS, is accumulated in cytoplasmic protein tau deposits in frontotemporal dementia and parkinsonism linked to chromosome 17 (Pick disease), Alzheimer disease and amyotrophic lateral sclerosis-parkinsonism/dementia complex 1 (Guam disease).

Proteolytically cleaved in the Golgi.
O-glycosylated with a core 1 or possibly core 8 glycan.