2. Cellular transport of proteins is very important in order for a cell to funct
ID: 91850 • Letter: 2
Question
2. Cellular transport of proteins is very important in order for a cell to function properly. For each of the mutations below, (1) explain what type of transport will be affected by explaining the correct transport process and where the problem will arise and (2) where the proteins that are transported incorrectly will be found (8 pts). (1) A mutation in N-acetyl transferase, the enzyme that adds N-linked glycosylation to proteins. (2) A mutation in the TIM22 complex. (3) A mutation that causes GTP to not be hydrolyzed in the cytosol (4) A mutation in the signaling molecule that causes the regulated secretion of insulin (a protein hormone)
Explanation / Answer
N-acetyltransferase is an enzyme that catalyzes the transfer of acetyl groups from acetyl-CoA to arylamines.They have wide specificity for aromatic amines, particularly serotonin, and can also catalyze acetyl transfer between arylamines without CoA.Mutation especially point mutation will lead to poor acetylation capacities.Its alleles fall into two classes, those that cause unstable protein and those which affect the activity of a folded protein.Deletions of few amino acids would result into cancer.
TIM 22(Translocase of inner membrane) a subunit of the TIM22 complex, forms a channel within the inner membrane and is referred to as the carrier translocase.It mediates the import and insertion of multi-pass transmembrane proteins, such as mitochondrial carrier family members, into the mitochondrial inner membrane. In the TIM22 complex, it constitutes the voltage-activated and signal-gated channel. Forms a twin-pore translocase that uses the membrane potential as external driving force in 2 voltage-dependent steps. Mediates the insertion of precursor proteins in a 3 step process.Thus its mutation would result in the disturbance of either voltage gated or signal gated channel or both.
GTPase-activating proteins or GTPase-accelerating proteins are a family of regulatory proteins whose members can bind to activated G proteins and stimulate their GTPase activity, with the result of terminating the signaling event. Regulation of G proteins is important because these proteins are involved in a variety of important cellular processes. The large G proteins, for example, are involved in transduction of signaling from the G protein-coupled receptor for a variety of signaling processes like hormonal signaling,and small G proteins are involved in processes like cellular trafficking and cell cycling. GAP’s role in this function is to turn the G protein’s activity off.
insulin signal transduction pathway is composed of trigger mechanisms (e.g., autophosphorylation mechanisms) that serve as signals throughout the cell. There is also a counter mechanism in the body to stop the secretion of insulin beyond a certain limit. Namely, those counter-regulatory mechanisms are glucagon and epinephrine. If a mutation occurs in this signalling molecule then obviously secretion of insulin could not be controlled.It would be produced beyond the normal limits or may not be produced at all devastating the whole of glucose metabolism.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.