TABLE 1.
Biological activities of the E. coli chaperone DnaK
| Activity | Cochaperone(s) | Substrate(s) | Reference(s) | Evolutionary relationship(s) |
|---|---|---|---|---|
| Foldase | DnaJ, GrpE | Unfolded/misfolded proteins | 15 | Hsp70 family member |
| Holding chaperone | Hsp31 | Unfolded/misfolded proteins | 21 | Presumed Hsp70 family member |
| Disaggregase | ClpB, IbpAB | Protein aggregates | 20, 25 | Species specificity of Hsp104/Hsp70 and ClpB/DnaK cooperativity; a disaggregation activity has not yet been identified in mammalian cells |
| Negative regulator of the heat shock response (proteolytic enhancer) | DnaJ, FtsH | Transcription factor σ32 | 22 | Not reported |
| Proteolytic enhancer | DnaJ, Lon, ClpP | Abnormal proteins | 13 | Not reported |
| Proteolytic enhancer | DnaJ, Lon, ClpP | Recombinant proteins | 10 | Not reported |