All 3 proteins bind with high affinity to the ATPase domain of Hsc70 and inhibit its chaperone activity in a Hip-repressible manner.

[12] That BAG3 mutations are responsible for familial dilated cardiomyopathy is confirmed by another study describing 6 new molecular variants (2 missense and 4 premature Stops ).

[13] In muscle cells, BAG3 cooperates with the molecular chaperones Hsc70 and HspB8 to induce the degradation of mechanically damaged cytoskeleton components in lysosomes.

This process is called chaperone-assisted selective autophagy and is essential for maintaining muscle activity in flies, mice and men.

[8] BAG3 is able to stimulate the expression of cytoskeleton proteins in response to mechanical tension by activating the transcription regulators YAP1 and WWTR1.