Figure 4

Activation of HSF-1 and HSP expression. HSF-1 normally resides in the cytosol in a multi-protein complex with HSP 72 and 90. Upon heat shock, HSPs dissociate from the multi-protein complexes, freeing HSF-1. Heat shock RNA (HSR) and elongation factor 1 (eEF1α) are recruited by HSF-1 allowing the transcription factor to trimerize. Upon trimerization, HSF-1 translocates to the nucleus, binds to HSEs and is phosphorylated allowing for HSP gene transcription.