BIOC 212 Lecture Notes - Lecture 4: Chaperone Dnaj, Groel, Groes
14 Oct 2015
School
Department
Course
Professor
Document Summary
Groel (one ring) no, substrate inside cavity no, substrate inside cavity. The heat shock response: heat shock followed by recovery period triggers a typical response in human cells, translation is inhibited immediately and slowly recovers, transcription of hsps is up-regulated (6-12 hours); transcription of other proteins is down-regulated. Increased degradation of unfolded proteins: protects from cell death (apoptosis) Hsf1: the hsf1 transcription factor mediates the heat shock response, hsf1 (60 kda) contains a dna binding domain, trimerization domain, and transcription activation domain. Inactive hsf1 is monomeric; active hsf1 is a trimer: active hsf1 recognizes hse (heat shock element) promoters. Protein modification: proteins can be chemically modified after translation. Covalent modification of n-terminus: polypeptide side chains can be covalently modified for various cellular functions. Can change surface or conformation of protein. Can create or block a binding site for other proteins. Many modifications are regulated and reversible: all modifications are mediated by enzymes, but follow the rules of organic chemistry.
