BIOL 230W Lecture Notes - Lecture 40: Unfolded Protein Response, Protein Folding, Sec61
Document Summary
Biol 230w lecture 40 misfolded proteins. Properly folded proteins traveling to a vesicle is an example of anterograde transport: forward transport. Defective sec61 cause build-up of misfolded proteins and decrease proteins (substrates) for the proteasomes. Leads to g1 arrest: adaptive, senses problem in cell. Results in upregulation of chaperone proteins and translational inhibition of some proteins. Response extends for long period of time apoptosis leading to cell death. Complex of proteins that degrades other proteins. Composed of 20s core protease subunit and two 19s regulatory subunits: 19s: controls entry and unfolding, 20s: structural and catalytic. Degraded peptides are short: 2-24 amino acids, broken down in cytosol into individual amino acids. If glycosylation is reduced, then highly branched glycan (sugars) are not attached to the mature protein. Er will first try to fix a misfolded protein. If it cannot be fixed, it will be sent for destruction.
