BIOL 3P30 Lecture Notes - Lecture 31: Steric Effects, Triage, Unfolded Protein Response
22 Aug 2015
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Proteins chaperoned: facilitate disaggregation, refolding, degradation molecular triage. Many are continually expressed- protein transport and delivery. Hsps are a component of the unfolded protein response (upr) The endoplasmic reticulum one is very understood but he"s showing us cytosolic. Hsp genes contain heat shock elements (hses) 5"ngaan3" Heat shock factor (hsf)- stimulates transcription of hsp genes by binding to hses. There are lots of these and they are numbered. Hsf1 exist in equilibrium with the single units and the trimer form (which is active) The regulatory model of transcriptional activation leading to the de novo synthesis of heat-shock proteins (hsps) Hsp70 physically binds to hsf to provide steric hindrance- does not trimerize: when heat shock occurs hsps are being pulled away you are left with hsf that can timerize. Once the stress goes away they will bind again to hsf. No stress-hsp70/90 binds hsf1-no trimerize-no stim. of hsp transcription. Heat shock proteins- stress proteins and constitutive chaperones.
