Cathepsin B (CTSB) Human Cellexp Active Protein

The protein encoded by this gene is a lysosomal cysteine proteinase composed of a dimer of disulfide-linked heavy and light chains, both produced from a single protein precursor. It is also known as amyloid precursor protein secretase and is involved in the proteolytic processing of amyloid precursor protein (APP). Incomplete proteolytic processing of APP has been suggested to be a causative factor in Alzheimer disease, the most common cause of dementia. Overexpression of the encoded protein, which is a member of the peptidase C1 family, has been associated with esophageal adenocarcinoma and other tumors. At least five transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

CTSB: Thiol protease which is believed to participate in intracellular degradation and turnover of proteins. Has also been implicated in tumor invasion and metastasis. Dimer of a heavy chain and a light chain cross-linked by a disulfide bond. Interacts with SRPX2. Belongs to the peptidase C1 family.

Protein type: Autophagy; Motility/polarity/chemotaxis; EC 3.4.22.1; Protease

Chromosomal Location of Human Ortholog: 8p22

Cellular Component: extracellular space; intracellular membrane-bound organelle; mitochondrion; perinuclear region of cytoplasm; lysosome; melanosome; nucleolus; extracellular region; intracellular

Molecular Function: peptidase activity; collagen binding; protein binding; proteoglycan binding; cysteine-type endopeptidase activity; cysteine-type peptidase activity

Biological Process: regulation of apoptosis; collagen catabolic process; extracellular matrix disassembly; extracellular matrix organization and biogenesis; proteolysis involved in cellular protein catabolic process; epithelial cell differentiation; regulation of catalytic activity; toll-like receptor signaling pathway; innate immune response; decidualization; proteolysis