PCSK1N

May act as a protein chaperone that prevents the aggregation of client proteins and plays a role in neuroprotection. Blocks the trans-synaptic spread of SNCA/alpha-synuclein in the brain. May form spheres that encapsulate client proteins (By similarity). May prevent aggregation of amyloid beta, IAPP/islet amyloid polypeptide, and SNCA/alpha-synuclein. Cannot disaggregate preformed fibrils. Additionally, may function in the control of the neuroendocrine secretory pathway by acting as a specific endogenous inhibitor of PCSK1. ProSAAS and Big PEN-LEN, both containing the C-terminal inhibitory domain, reduce the activity of the 87 kDa form of PCSK1, but not the autocatalytically derived 66 kDa form, in the endoplasmic reticulum and Golgi. May control the intracellular timing of PCSK1 rather than its total level of activity and slows down convertase-mediated processing of proopiomelanocortin and proenkephalin (By similarity)..

Function from UniProtKB (Q9UHG2), read 2026-09-23. CC BY 4.0.