Cathepsin B

Cathepsin B is an enzymatic protein belonging to the peptidase or protease families. In humans, it is coded by the CTSB gene.

Function

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 a member of the peptidase C1 family. Cathepsin B was once suspected as a candidate protease participating in the conversion of β-amyloid precursor protein into the amyloid plaques found in Alzheimer's disease patients. However, this function is now known to be mediated by BACE1 protease. It is now thought that cathepsin B can degrade β-amyloid precursor protein into harmless fragments. Thus, it is conceivable cathepsin B may play a pivotal role in the natural defense against Alzheimer's disease.^[1][2]. Overexpression of cathepsin B has been associated with esophageal adenocarcinoma and other tumors. At least five transcript variants encoding the same protein have been found for this gene.^[3]

See also

• Cathepsins

References

1. ^ Mueller-Steiner S, Zhou Y, Arai H, Roberson E, Sun B, Chen J, Wang X, Yu G, Esposito L, Mucke L, Gan L (2006). "Antiamyloidogenic and neuroprotective functions of cathepsin B: implications for Alzheimer's disease". Neuron 51 (6): 703–14. doi:10.1016/j.neuron.2006.07.027. PMID 16982417. 
2. ^ "Enzyme shreds Alzheimer's protein". 2006-09-21. http://www.scienceblog.com/cms/enzyme-shreds-alzheimers-protein-11550.html. Retrieved on 2007-11-07. 
3. ^ "Entrez Gene: CTSB cathepsin B". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1508. 

Further reading

External links

• MeSH Cathepsin+B

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