Large proline-rich protein BAG6 (BAG6)

Large proline-rich protein BAG6 (BAG6) is a multifunctional ATP-independent molecular chaperone and adaptor protein central to cellular protein quality control[1][3][4][5]. It functions as part of the BAG6/BAT3 complex, which maintains misfolded or hydrophobic proteins in a soluble state and directs them either to the endoplasmic reticulum for membrane insertion or to the proteasome for degradation. BAG6 regulates various cellular processes including apoptosis, autophagy, proteostasis, and immune response. It acts as a switch between autophagy and apoptosis during cellular stress, is essential for post-translational targeting of tail-anchored proteins, and serves as a ligand for natural killer (NK) cell receptor NKp30, thereby influencing immune surveillance in health and cancer[1][2][3][4][5]. Disruption or modulation of BAG6 can have wide-ranging effects, from protein aggregation and cell death to altered immune responses and embryonic lethality in animal models. No targeted drugs or inhibitors are yet established against BAG6 for clinical use.

Other names

BCL2-associated athanogene 6BAG cochaperone 6HLA-B-associated transcript 3 (BAT3)Protein G3Protein ScytheBAG family molecular chaperone regulator 6D6S52E

Facilitates targeting of misfolded or hydrophobic proteins either for endoplasmic reticulum (ER) delivery or proteasomal degradation by acting as part of a cytosolic quality control complex[1][3][5]. Acts as a molecular chaperone, holding client proteins in a soluble state and preventing aggregation[4][5]. Interacts with natural killer (NK) cell receptors (e.g., NKp30/NCR3) as a ligand, modulating immune cytotoxicity[3][4]. Mediates apoptosis, sometimes via interaction with apoptosis factors or regulating p53 signaling[2][3]. Modulates autophagy pathways, depending on its cellular localization and cleavage state[2].