Cystatin F is a cathepsin C-directed protease inhibitor regulated by proteolysis.
EMBO J
; 27(3): 499-508, 2008 Feb 06.
Article
em En
| MEDLINE
| ID: mdl-18256700
ABSTRACT
Cystatins are a family of naturally occurring cysteine protease inhibitors, yet the target proteases and biological processes they regulate are poorly understood. Cystatin F is expressed selectively in immune cells and is the only cystatin to be synthesised as an inactive disulphide-linked dimeric precursor. Here, we show that a major target of cystatin F in different immune cell types is the aminopeptidase cathepsin C, which regulates the activation of effector serine proteases in T cells, natural killer cells, neutrophils and mast cells. Surprisingly, recombinant cystatin F was unable to inhibit cathepsin C in vitro even though overexpression of cystatin F suppressed cellular cathepsin C activity. We predicted, using structural models, that an N-terminal processing event would be necessary before cystatin F can engage cathepsin C and we show that the intracellular form of cystatin F indeed has a precise N-terminal truncation that creates a cathepsin C inhibitor. Thus, cystatin F is a latent protease inhibitor itself regulated by proteolysis in the endocytic pathway. By targeting cathepsin C, it may regulate diverse immune cell effector functions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeo Hidrolases
/
Inibidores de Proteases
/
Biomarcadores Tumorais
/
Cistatinas
/
Catepsina C
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
EMBO J
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Reino Unido