Hsp90 chaperone control over transcriptional regulation by the yeast Slt2(Mpk1)p and human ERK5 mitogen-activated protein kinases (MAPKs).

Cell integrity MAPK (mitogen-activated protein kinase) function can be provided in yeast cells by either the native Slt2(Mpk1)p of yeast or by a heterologously expressed human ERK5 (extracellular-signal-regulated kinase 5). Both of these MAPKs need the Hsp90 (heat-shock protein 90) chaperone for their activation, so that when Hsp90 function is compromised their activities are low. This, in turn, affects the capacity of these MAPKs to control the transcription factors that regulate cell integrity genes.