Proteosome inhibitors: A targeted therapy

Proteasome inhibition is a valid anticancer strategy. The ubiquitin proteasome pathway plays acritical role in regulating many processes in the cell which are important for tumour cell growth and survival. The proteosomal degradation is a highly complex and regulated process and is essential for cellular regulatory mechanism and maintaining homeostasis. In the ubiquitin proteasome pathway, the ubiquitin tagged proteins are recognised by 19s proteasomes and it is untagged by the same. The resultant protein substrates are unfolded by the enzyme ATPases; the substrates are fed into inner catalytic compartment of 20s proteasomes followed by the opening of molecular gate channel. These unfolded proteins are then hydrolyzed by 6 active proteolytic sites like Chymotrypsin like (CT-L), Caspase like (C-L) and trypsin like(T-L)on β-subunits into small polypeptides. This activity of proteasomes is inhibited by the proteasome inhibitors. Development of Proteosome inhibitors shows the hope for the cancer patients. This review facilitates easy understanding of the concepts of proteasome inhibitors, dealing in brief about the ubiquitin proteasome pathway, Biological effects of Pi,Therapeutic applications andto enlighten the approved drugs for clinical practice.