CTSW Proteins

Protein Information

Cathepsin W (lymphopain) and cathepsin F comprise a novel subgroup of cathepsin proteases, and are phylogenetically distinct from other human cathepsins. The cathepsin W gene maps to chromosome 11q13.1 and contains ten exons with introns ranging from 81-119 bp. Cathepsin W protein is expressed specifically in CD8+ T lymphocytes. The expression of cathepsin W first occurs during the differentiation of thyrocytes to CD8+ T lymphocytes, just as the thymocytes cease expression of CD4+ receptors. In transfected Cos-7 and HeLa cells, cathepsin W localizes within the rough endoplasmic reticulum. Cathepsin W contains a unique 21 amino acid peptide insertion between the active site histidine and asparagine residues, in addition to a distictive 8-amino acid carboxy-terminal extension. An extended loop struc-ture in the second or beta-sheet domain and an additional disulfide bind are two of several signature features of cathepsin W. Other features of cathepsin W include an additional cysteine, an S2 pocket and an additional residue. Cathepsin W may exist as a dimer with each monomer forming a disulfide bond.

Synonyms

cathepsin W; Ctsw; lymphopain; LYPN