Recombinant Human Cathepsin S (CTSS)

Uniprot Id

P25774

Target Species

Human

Target Name

CTSS

Target Full Name

Cathepsin S

Target Function

Thiol protease. Key protease responsible for the removal of the invariant chain from MHC class II molecules and MHC class II antigen presentation. The bond-specificity of this proteinase is in part similar to the specificities of cathepsin L.

Target Subcellular Location

Lysosome. Secreted. Cytoplasmic vesicle, phagosome.

Target Protein Families

Peptidase C1 family

Target Research Area

Immunology

Target Synonyms

Cathepsin S; CathepsinS; CATS_HUMAN; Ctss

Target Background

The preproprotein encoded by this gene, a member of the peptidase C1 family, is a lysosomal cysteine proteinase that participates in the degradation of antigenic proteins to peptides for presentation on MHC class II molecules. The mature protein cleaves the invariant chain of MHC class II molecules in endolysosomal compartments and enables the formation of antigen-MHC class II complexes and the proper display of extracellular antigenic peptides by MHC-II. The mature protein also functions as an elastase over a broad pH range. When secreted from cells, this protein can remodel components of the extracellular matrix such as elastin, collagen, and fibronectin. This gene is implicated in the pathology of many inflammatory and autoimmune diseases and, given its elastase activity, plays a significant role in some pulmonary diseases. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene.