Entrez Summary: The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and kininogens. This gene encodes a stefin that functions as an intracellular thiol protease inhibitor. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. The protein is thought to play a role in protecting against the proteases leaking from lysosomes. Evidence indicates that mutations in this gene are responsible for the primary defects in patients with progressive myoclonic epilepsy (EPM1). One type of mutation responsible for EPM1 is the expansion in the promoter region of this gene of a CCCCGCCCCGCG repeat from 2-3 copies to 30-78 copies. [provided by RefSeq, Jul 2016].
UniProt Summary: This is an intracellular thiol proteinase inhibitor. Tightly binding reversible inhibitor of cathepsins L, H and B.
Pfam DomainsGO Terms
Pfam Domains
Cystatin
GO Terms
cysteine-type endopeptidase inhibitor activity
endopeptidase inhibitor activity
tertiary granule lumen
adult locomotory behavior
protease binding
secretory granule lumen
ficolin-1-rich granule lumen
adult behavior
locomotory behavior
negative regulation of endopeptidase activity
negative regulation of peptidase activity
negative regulation of proteolysis
collagen-containing extracellular matrix
regulation of endopeptidase activity
regulation of peptidase activity
negative regulation of hydrolase activity
neutrophil degranulation
neutrophil activation involved in immune response
neutrophil mediated immunity
neutrophil activation
granulocyte activation
leukocyte degranulation
myeloid leukocyte mediated immunity
myeloid cell activation involved in immune response
behavior
myeloid leukocyte activation
leukocyte activation involved in immune response
cell activation involved in immune response
regulated exocytosis
regulation of proteolysis
leukocyte mediated immunity
negative regulation of catalytic activity
exocytosis
nucleolus
leukocyte activation
secretion by cell
negative regulation of cellular protein metabolic process
export from cell
cell activation
immune effector process
negative regulation of protein metabolic process
secretion
negative regulation of molecular function
regulation of hydrolase activity
RNA binding
extracellular space
immune response
extracellular region
vesicle-mediated transport
CRISPR Data
Compound HitMost Correlated Genes in ChemogenomicsTissues where Essential in the Avana Dataset (DepMap 20Q1)