Cathepsin B (pro) (CTSB)

Cathepsin B (CTSB) is a normal lysosomal proteinase that is expressed in all cells. It is a cysteine endoproteinase structurally and functionally related to the papain family of proteases. CTSB is synthesized as an inactive 43 kDa pro enzyme which, by removal of a 62 amino acid propeptide, is activated to the single chain form of 31 kDa or the two chain form (25 and 5 kDa subunits). Matured CTSB is normally localized in the lysosomes where it functions in protein turnover. In tumor cells and in cells exposed to mitogens, CTSB displays altered cellular trafficking resulting in the secretion of the 43 kDa precursor. Elevated levels of CTSB correlate with malignancy suggesting that this enzyme may be a useful prognostic marker for several types of human cancers. CTSB has also been implicated in the pathogenesis of rheumatoid arthritis, muscular dystrophy and tumor metastasis.

Swiss-Prot Accession Number: P07858

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This analyte is not currently part of Myriad RBM's testing menu.

Myriad RBM Publications Publications
Proteomic biomarkers of cognitive impairment in obstructive sleep apnea syndrome (2018) Lal C, Hardiman G, Kumbhare S, Strange C Sleep and Breathing
Circulating Biomarkers and Outcome from a Randomised Phase Ii Trial of Sunitinib Vs Everolimus for Patients with Metastatic Renal Cell Carcinoma (2016) Voss MH, Chen D, Marker M, Hakimi AA, Lee C-H, Hsieh JJ, Knox JJ, Voi M, Motzer RJ British Journal of Cancer
A guidance for renal biomarker lead optimization and use in translational pharmacodynamics (2010) Ozer JS Drug Discov Today15: 142-7.