Bcl-2

Bcl-2 (B-cell lymphoma 2), encoded in humans by the BCL2 gene, is the founding member of the Bcl-2 family of regulator proteins that regulate cell death (apoptosis), by either inducing (pro-apoptotic) or inhibiting (anti-apoptotic) apoptosis. Bcl-2 is specifically considered an important anti-apoptotic protein and is thus classified as an oncogene.

Bcl-2 derives its name from B-cell lymphoma 2, as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in follicular lymphomas. Orthologs (such as Bcl2 in mice) have been identified in numerous mammals for which complete genome data are available.

Like BCL3, BCL5, BCL6, BCL7A, BCL9, and BCL10, it has clinical significance in lymphoma.

Isoforms

The two isoforms of Bcl-2, Isoform 1, also known as 1G5M, and Isoform 2, also known as 1G5O/1GJH, exhibit a similar fold. However, results in the ability of these isoforms to bind to the BAD and BAK proteins, as well as in the structural topology and electrostatic potential of the binding groove, suggest differences in antiapoptotic activity for the two isoforms