Fig. 5

Proposed model of MYC-mediated BAG1 regulation and distinct functions of BAG1 isoforms. MYC activates gene transcription of BAG1 which produces BAG1 mRNA with three translation start sites that encode distinct protein isoforms BAG1L, M, and S. Nuclear BAG1L and BAG1M cooperate with transcription factors to regulate gene expression. Cytoplasmic BAG1M and BAG1S interact with HSP70 to modulate chaperone activity. As reported here, HSP70/BAG1S complex upregulates an array of proteins and inhibits MYC-driven apoptosis