Cathepsins are papain family cysteine proteinases that represent a major component of the lysosomal proteolytic system. In general, cathepsins contain a signal sequence, followed by a propeptide and then a catalytically active mature region. The very long (251-amino acid residues) proregion of the cathepsin F precursor contains a C-terminal domain similar to the pro-segment of cathepsin L-like enzymes, a 50-residue flexible linker peptide, and an N-terminal domain predicted to adopt a cystatin-like fold. The cathepsin F proregion is unique within the papain family cysteine proteases in that it contains this additional N-terminal segment predicted to share structural similarities with cysteine protease inhibitors of the cystatin superfamily. This cystatin-like domain contains some of the elements known to be important for inhibitory activity. CTSF encodes a predicted protein of 484 amino acids that contains a 19-residue signal peptide. Cathepsin F contains five potential N-glycosylation sites, and it may be targeted to the endosomal/lysosomal compartment via the mannose 6-phosphate receptor pathway. The cathepsin F gene is ubiquitously expressed, and it maps to chromosome 11q13, close to the gene encoding cathepsin W.[7]
Nägler DK, Sulea T, Ménard R (1999). "Full-length cDNA of human cathepsin F predicts the presence of a cystatin domain at the N-terminus of the cysteine protease zymogen". Biochem. Biophys. Res. Commun. 257 (2): 313–8. doi:10.1006/bbrc.1999.0461. PMID10198209.
Wex T, Levy B, Wex H, Brömme D (1999). "Human cathepsins F and W: A new subgroup of cathepsins". Biochem. Biophys. Res. Commun. 259 (2): 401–7. doi:10.1006/bbrc.1999.0700. PMID10362521.
Wex T, Wex H, Brömme D (2000). "The human cathepsin F gene--a fusion product between an ancestral cathepsin and cystatin gene". Biol. Chem. 380 (12): 1439–42. doi:10.1515/BC.1999.185. PMID10661872. S2CID28469574.
Kaakinen R, Lindstedt KA, Sneck M, et al. (2007). "Angiotensin II increases expression and secretion of cathepsin F in cultured human monocyte-derived macrophages: an angiotensin II type 2 receptor-mediated effect". Atherosclerosis. 192 (2): 323–7. doi:10.1016/j.atherosclerosis.2006.08.001. PMID16963053.
External links
The MEROPS online database for peptidases and their inhibitors: C01.018