BAG1 Human

BAG1 is part of the BAG family of proteins, which are evolutionarily conserved and function as co-chaperones . The BAG1 gene was first identified in a screen of a small Mus musculus embryo cDNA library using a recombinant human BCL2 protein as bait to identify BCL2 interactors . The BAG1 protein enhances the anti-apoptotic effects of BCL2 and represents a link between growth factor receptors and anti-apoptotic mechanisms .

The BAG1 protein contains a BAG domain, which is essential for its interaction with Hsp70/Hsc70 proteins. This interaction is critical for the protein’s role in the cellular stress response . BAG1 functions in a wide range of cellular processes, including:

• Apoptosis: BAG1 enhances the anti-apoptotic effects of BCL2, thereby promoting cell survival .
• Protein Refolding and Degradation: BAG1 acts as a co-chaperone, assisting in the refolding and degradation of misfolded proteins .
• Tumorigenesis: Overexpression of BAG1 has been observed in various cancers, indicating its role in tumorigenesis .

Multiple protein isoforms of BAG1 are encoded by its mRNA through the use of a non-AUG (CUG) initiation codon and three alternative downstream AUG initiation codons . These isoforms are differentially expressed in various tissues and have distinct cellular localizations and functions .

BAG1 is overexpressed in a range of cancers, including breast cancer, colorectal cancer, and acute myeloid leukemia . Its role in enhancing the anti-apoptotic effects of BCL2 makes it a potential target for cancer therapy. Research is ongoing to understand the mechanisms by which BAG1 contributes to tumorigenesis and to develop therapeutic strategies targeting BAG1 .