BIOLOGY 151 Lecture Notes - Lecture 7: Proteasome, Lysosome, Ubiquitin Ligase
Document Summary
The 3rd perusall assignment on topic 3 is due friday, september 30th at 11:59pm. Moodle pre-lecture assignment 3 is open and due sunday night (on topic 3: cell cycle) Feedback loop when a downstream component in a linear pathway regulates an upstream component in its on pathway. Negative feedback downstream component has a negative effect on an upstream component where it stops or slows down production leads to less transduction. Ubiquitin protein that tags unwanted protein for destruction: ubiquitin ligase enzyme for putting ubiquitin onto the target protein. After a protein is tagged, an enzyme called proteasome will cut apart (degrade) the protein. Ubiquitin mediated proteolysis is regulated by e1,e2,e3 proteins: e3 protein has specific interaction sites for its target binding site. It will use ubiquitin to target the protein, in which proteasome will identify and degrade the target protein. Target proteins usually include old or misfolded proteins that the cell deems as no longer necessary.
