Table 1.
Redundancy of cytosolic Hsp70 system components
| Chaperone family | Membersa | Function |
|---|---|---|
| Hsp70 | Ssa1, Ssa2, Ssa3, Ssa4 | Bind unfolded parts of proteins; assists protein folding, translation, translocation, degradation; prevents protein aggregation |
| Hsp40 (J-proteins) | Ydj1, Sis1 | Bind Hsp70 NBD to stimulate Hsp70 ATPase; binds unfolded parts of proteins to prevent protein aggregation, presents substrate to Hsp70 |
| NEF | Sse1, Sse2 (Hsp110 family); Fes1(HspBP1 family); Snl1 (Bag1 family) | Bind Hsp70 NBD to promote release of ADP, which allows rebinding of ATP |
| TPR co-chaperones | Sti1, Cns1, Cpr7 | Bind Hsp70 C-terminus, stimulates Hsp70 ATPase, bridges Hsp70 to Hsp90 system |
a
Major relevant cytosolic family members.