Cathepsin Z

Cathepsin Z or cathepsin X is a protein that in humans is encoded by the CTSZ gene. The encoded protein has also been known as cathepsin X and cathepsin P.

Structure

At least two transcript variants of this gene have been found, but the full-length nature of only one of them has been determined.The gene has 6 exons and locates at chromosome band 20q13.32.

Function

The protein encoded by this gene is a lysosomal cysteine proteinase and member of the peptidase C1 family. It exhibits both carboxy-monopeptidase and carboxy-dipeptidase activities. Up to date, nine human cysteine proteinases have been identified, including cathepsin B, cathepsin C, cathepsin H, cathepsin K, cathepsin L, cathepsin L2, cathepsin O, cathepsin S, and cathepsin W. These cysteine proteinases belong to the papain family and represent a major component of the lysosomal proteolytic system.In addition to playing a critical role in protein degradation and turnover, these proteinases appear to play an extracellular role in a number of normal and pathological conditions.

Clinical Significance

This gene is expressed ubiquitously in cancer cell lines and primary tumors and, like other members of this family, may be involved in tumorigenesis.

External links

• The MEROPS online database for peptidases and their inhibitors: C01.013