1. Explain the signaling cascade downstream of GPCR: • How trimeric G-protein is activated and inactivated?...
-Describe how trimeric G proteins get activated and inactivated - Name the two common second messengers In what signaling pathways do these messengers get activated (Yes, you do need to know the names of the key players in the pathway!)? What can the second messenger then do? What two criteria are needed for activation of a receptor tyrosine kinase? -Describe how monomeric Ras is activated and what does Ras do upon activation. (Again, you must know the signaling pathway) -Describe...
You are interested in cell size regulation and discover that signaling through a GPCR is important in controlling cell size in rat white blood cells. The G protein downstream of this receptor activates adenylyl cyclase, which ultimately leads to the activation of PKA. You find that cells that lack the GPCR are 15% smaller than normal cells, whereas cells that express a mutant, constitutively activated version of PKA are 15% larger than normal cells. Furthermore, the normal blood cells become...
Describe how protein kinases and phosphates change the activity of downstream proteins and explain what is meant by "kinase cascade" by using the mitogen activated protein kinase pathways as an example.
Some G-protein coupled receptors (GPCRs) are associated with a protein called RGS, which stimulates the GTPase activity of the receptor’s G-protein. What effect does RGS have on GPCR signaling? a. Signaling events are activated (upregulated) due to an increase in cAMP levels. b. Signaling events are downregulated due to disruption of the receptor-ligand interaction. c. Signaling events are activated as PKA as inhibition from the regulatory subunits is abolished. d. Signaling events are downregulated as the G-protein adopts its inactive...
Explain using simple details and correspoding "ON" "OFF" signals. Describe signaling through the G-protein linked receptor. Be sure to include the details of the receptor the associating G protein and its subunits, and the events in the sequence they occur. Be sure to include the reset for every step that is activated. Describe the signaling pathway that involves cAMP and G proteins. Include how each step is rest. Include dephosphorylation events. Assume involvement of PKA
Activity 4. Receptor signaling pathway A model of a G protein receptor signaling pathway is represented below. Activation of the signaling pathway results in a cell secreting a neurotransmitter through exocytosis. Activated - Activated adenylyl receptor cyclase GTP АТР CAMP Active G protein Protein- kinase A Inactive Active Protein targets Phosphate group A. Different steps in a signaling pathway can amplify the initial signal of one ligand binding to one receptor. Choose one step in the pathway below that results...
4. What type of membrane protein is this G-protein Coupled Receptor (GPCR) integral or peripheral) and describe the features that contribute to its function in the cell? 5. How does the low GTPase activity in the mutated protein result in the constitutive activation of the G a protein and adenylate cyclase?
The small monomeric G protein Ras is an important component of most receptor tyrosine kinase signaling pathways. It can regulate a number of downstream signaling components, perhaps most famously the MAPK cascade. Unlike other monomeric G proteins that we have discussed previously in class, Ras is anchored at the plasma membrane by a covalently bound lipid anchor. If Ras was specifically mutated so that it did not get this lipid modification (but was otherwise completely unchanged), what do you hypothesize...
1. What is the difference between: a. A G Protein and G Protein-Coupled Receptor b. Trimeric and Monomeric G proteins
Ligand binding to a G-protein coupled receptor (GPCR) results in activation of a single G- protein and then the receptor deactivates. O True False When an activated receptor relays the signal along more than one pathways this is called convergence. O True OFalse Which of the following best describes digestive enzymes? O Hydrolases OLigases Kinases Transferases Decarboxylases Most digestive enzymes are released from cells in an inactive form. True False denatures Protein digestion in humans (and other mammals) begins in...