Ch 15D Assignment Flashcards
All GPCRs act by increasing cAMP?
TRUE
FALSE
FALSE
What domain of son of sevenless (Sos) recruits it to the plasma membrane so that it gets in close proximity to Grb2?
PTB
SH3
SH2
PH
PH
Mutations altering the GPCR binding interface in arrestin are likely to………………
inhibit GPCR signaling.
inhibit phosphorylation by GPCR kinases.
prevent desensitization of GPCRs.
inhibit G-protein activation.
prevent desensitization of GPCRs.
For Notch to be recognized by Delta, it has to be transported to the…………..
golgi lumen
plasma membrane
endoplasmic reticulum
nucleus
plasma membrane
PI3 Kinase primarily phosphorylates……………
tyrosine residues
serine residues
threonine residues
phospholipids
phospholipids
Which of these enzymes is bound to the cytosolic side of the plasma membrane and converts PI(4,5)P2 to IP3 and diacylglycerol?
PKA
Adenylyl cyclase
phospholipase C-Beta
PI 3-kinase
phospholipase C-Beta
Why doesn’t the beta subunit of the trimeric G-protein need a lipid anchor like the alpha and gamma subunits?
it effectively uses the alpha’s anchor.
it effectively uses the gamma’s anchor.
it does not need to be near the plasma membrane.
it uses a PH domain to bind a phosphoinositide docking site.
it effectively uses the gamma’s anchor.
Select the mechanism of activation of AKT by PI-3K ?
It phosphorylates lipids that create a docking site for AKT.
It activates the receptor tyrosine kinase activity to directly phosphorylate AKT.
It is a kinase that directly phosphorylates AKT.
It creates DAG and IP3 that activate AKT.
It phosphorylates lipids that create a docking site for AKT.
G-proteins are bound to GPCRs………………….
at the extracellular surface of the plasma membrane.
at the intracellular side of the plasma membrane.
deep within the alpha-helical pocket in the GPCRs.
buried fully within the lipid bilayer.
at the intracellular side of the plasma membrane.
Mutations in Ras are found in a majority of cancers. Which of these mutations will lead to permanent activation of Ras-signaling?
Mutations that inhibit Ras-GTPase activity
Mutations that activate Ras-GAP
Mutations that inhibit Ras-GEF activity
Mutations that inhibit Raf-activity
Mutations that inhibit Ras-GTPase activity
Which of these kinases is activated by binding to diacylglycerol that is released by breakdown of PI(4,5)P2?
Protein Kinase A
Adenylyl cyclase
Protein Kinase C
Phospholipase
Protein Kinase C
Which of these factors belong to a family of local mediators that were originally identified as the gene important for wing development in Drosophila?
Wnt
Beta-catenin
Ras
Raf
Wnt
Which mechanism is NOT likely to sharpen the cellular response to a signal?
A positive feedback of moderate strength sharpens the response to the signal.
Sharper responses occur if target activation requires more than one phosphate.
Sharper responses occur if more than one signal molecule binds to the target.
Activating enzymes for the forward and back reactions sharpens the response.
Activating enzymes for the forward and back reactions sharpens the response.
