Describing BCL- Family

The following note is a review on the Bcl-2 family protein encoded by gene BCLAF1. Bcl-2 proteins are apoptosis regulators that regulate mitochondrial outer membrane permeabilization (MOMP) and release cytochrome C (1-3) and can be pro-apoptotic or anti-apoptotic. There are totally 25 genes involved in Bcl-2 family. The BH family can be classified into 4 domains (BH1-4) which regulate protein interactions. Based upon function and sequence homology, BH family can be divided into pro-apoptotic which include Bcl-2, Mcl-1, Bcl-xL, A1 and Bcl-w. Pro-apoptotic proteins include Bax, Bak and Bok, and BH3 only proteins Bad, Bik, Bid, Puma, Bmf, Bim, Noxa and Hrk. The interactions between death promoting and death suppressing Bcl-2 family members has led to a rheostat model in which ration of pro-apoptotic and anti-apoptotic proteins control cell fate. The BH3-only members can bind and antagonize pro-survival members leading to increased apoptosis.