Nst 160 Midterm 1 (Lec 1-5) 68 Correctly Answered Questions Latest Update

how does GCN2 sense a lack of AAs? which domain of GCN2 is involved? {Ans: - When AA is limited (starvation mode), uncharged tRNAs accumulate and activate GCN2 - The HisRS part of GCN2 activates KD (kinase domain), causing eIF2alpha to be phosphorylated - Once eIF2-P, that inhibits eIF2B (exchange factor), inhibiting protein synthesis}2. In step 2 of eIF2 pathway: What does eIF5 do? {Ans: After met-tRNAi interacts w cap-binding complex, eIF2 is released eIF5 is the GTPase activator protein that hydrolyzes GTP to GDP.}Why do mutations in L-ferritin IRE matter? {Ans: - IRE is the binding pocket of IRP and mutations reduce the affinity IRPs have for the L-ferritin IRE - Results in overproduction of protein regardless of whether [iron] high / low - L-ferritin overexpression can increase levels of protein in tissues, serum, eye - Hereditary disease: HHCS (crystalized cataracts)}Briefly describe the three methods of AMP activating AMPK? {Ans: 1. allosteric activation 2. stimulation of phosphorylation 3. inhibition of regulatory Thr dephosphorylation via phosphatases}Knowing the roles of BMAL1-CLOCK driving expression of Per & Cry genes, tell me about the loop involving different set of proteins and how that works for mice: {Ans: 1.