Which of the following steps amplify the epinephrine signal response in cells: receptor activation of G protein, G protein activation of adenylyl cyclase, cAMP activation of PKA, or PKA phosphorylation of glycogen phosphorylase kinase (GPK)? Which change will have a greater effect on signal amplification: an increase in the number of epinephrine receptors or an increase in the number of Gαs  proteins?

A signaling molecule M is active when it is phosphorylated (M-P). The M-P has downstream target molecules in nucleus. Provide a possible mechanism by which M does its job

Which is a correct explanation of an aspect within G protein signaling pathway? ATP powers the G protein to cause it to move and activate an enzyme O GTP activates the G protein causing it to move to activate the next protein O The receptor is active when bound to GTP GTP causes the G protein to activate and bind to the receptor

Binding EGF to the EGF receptor causes phosphorylation of tyrosines on the cytoplasmic tail of the receptor. Which of the following best describes the mechanism by which this phosphorylation activates downstream signaling complexes? Select one    A. Causes degradation of receptor by proteasome pathway   B. Causes EGF receptor to be internalized so it can interact directly with downstream signaling molecules   C. Tyrosine phosphorylation alters 3D structure of downstream signaling proteins causing them to change from an inactive to active conformation   D. Causes release of EGF from receptor   E. Alters the localization of downstream signaling partners in the cytoplasm

When a signal binds to the Tyrosine kinase receptor (RTK), you have studied that a list of events occur sequentially. Map the events in the correct order from 1st to the last step.

Arrange following the boxed information in sequence regarding the dissociation and reassociation of G proteins following the activation of a G protein coupled receptor. GTP-bound Ga, dissociates from B and y cuhunits Gas exchanges GTP for GDP Gas reassociates with By subunits and the rorentor reforms Binding of the ligand to a G-protein rounled recentor GTP-bound Gas binds and activates adenvlul rurlase GTP is hydrolyzed and GDP bound Gas suhunit dissoriates Conformational change Increased synthesis of CAMP from ATP

1) the Ga subunit has a mutation resulting in increased GTPase activity? Why is the GPCR referred to as a GEF? What would occur in G protein signalling if

Arrange the following in correct order in which G-protein coupled receptor systems are activated:   Drug Receptor Protein kinase A Adenylyl cyclase G-protein Cellular response

Which processes are involved in the signaling pathway from insulin to glycogen synthase kinase 3 (GSK3) inactivation (select all that apply)? O protein kinase B being activated by a protein kinase known as PDK-1 O activation of insulin receptor substrate-1 (IRS-1) by phosphorylation O phosphatidylinositol 3-kinase associating with IRS-1 generates phosphatidylinositol 4,5-bisphosphate O protein kinase B phosphorylating GSK3, resulting in its activation O insulin binding to a tyrosine kinase receptor

From the Hill Plot below, the KD of the first binding event for the receptor-ligand system under study is: 10 8 6 4 2 0 -2 4 6 8 10 (0=1) 601 log -4- -6 -6 -4 -2 0 2