anti-BAG-1 (human), Rabbit Monoclonal (RM356)

BAG-1 belongs to a family of evolutionary conserved proteins, containing an approximately 110 amino acid sequence termed the BAG domain that defines the protein family. BAG1 was identified in a screen of interacting proteins of the anti-apoptotic protein BCL2. BAG1 shares no significant homology with BCL2 or other BCL2 family proteins, which can form homo- and heterodimers. However, coexpression of BAG1 and BCL2 provided markedly increased protection from cell death induced by several stimuli. BAG1 itself is made up of different isoforms translated from a single mRNA by alternative translational initiation, resulting in similar carboxy-terminal sequences but different N-terminal sequences. In humans, there are four BAG1 isoforms (BAG1L, 1M, 1 and 1S). The multiple protein isoforms interact with diverse partners, including chaperones Hsc70/Hsp70, Ser/Thr kinase Raf-1 and Bcl-2, to promote cancer cell survival. The BAG-1L isoform specifically binds to and increases the transcriptional activity of oestrogen receptor in cells, and in some, but not all studies, BAG-1 expression is predictive of clinical outcome in breast cancer.