BIOL 300 Lecture Notes - Glycosylation, Eif2, Protein Folding

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 300
• Professor: Siegfried Hekimi

Document Summary

During translation: mrna is translated, normally, into a cytosolic protein, other proteins are translated from mrna directly into the. Various chaperones are required to catalyze the folding reaction: whenever the cell is under stress, these chaperones are affected to regulate levels of translation and folding. This illicits an initial short term response to downregulate translation, followed by a long term response which would upregulate transcription and translation of certain genes which are able to help fold proteins correctly (i. e. chaperones, lipids, glycosylation proteins, etc. ) In vitro, scientists can feed cells with certain chemicals, like tunicamycin, to induce protein unfolding to look at the mechanisms of the upr. We will first look at the mechanism behind upregulation of gene expression (long term response), which depends on a chaperone protein known as bip, which is necessary for folding proteins in the er. In addition to binding unfolded er proteins, bip can bind to transmembrane proteins called ire1.