BIOL 361 Study Guide - Vasodilation, Autophosphorylation, Growth Factor
Document Summary
Ras protein->ras protein bind+hydrolyze gtp->function as switches by cycling btw the active state(gtp=bound) and the inactive state(gdp=bound)-catalyzed by gtpase-activating proteins(gaps)+guanine nucleotide-releasing proteins(gnrps)-receptor tyrosine kinases signal thru. Gaps+gnrps to regulate ras-activate a serine/threonine phosphorylation cascade in animal cells-activated ras signals to a map-kinase-kinase- kinase(mapkkk)->phosphorylates a map-kinase-kinase(mapkk)- >phosphorylate a map-kinase(mapk)->phosphorylate other protein kinases, cellular proteins+transcription factors(elk-1and jun)->regulate the transcription of other transcription factors+various genes=>amplify original chem. signal-30%human cancers-involve mutations in the genes encoding. Ras(turn the ras protein on constitutively-active when there"s no ligand- , , )- subunit-contains the binding sites for the guanosine nucleotides- . + subunits-bound to each other= subunit,a single functional group 1. ligand binds to a g-protein-coupled receptor 2. receptor chnge shape 3. send a signal to the subunit->conformational chnge in g-protein 4. release gdp. +bind a molcle of gtp+become activated 5. activated subunit dissociates from the subunit->both go on to interact w/ downstream targets(activated.
