Cell Communication – RTKs and GPCPs – Flashcards

How can a ligand have different effects in different tissues? Vasopressin is a hormone that is primarily released when the body is low on water. Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output. However, vasopressin also has additional functions in other tissues such as the brain and blood vessels, which are not directly involved in urine production. How could it be possible for vasopressin to trigger different responses in different tissues?

Estrogen receptor inhibitor: You are interested in developing an inhibitor for the estrogen receptor. You have identified a molecule that is small and hydrophilic. In a test tube, this inhibitor binds tightly to the estrogen receptor, and inhibits the interaction of the receptor with estrogen. Do you think that this molecule will be an effective inhibitor of the estrogen receptor in cells?

The space into which neurotransmitters are released: In synaptic signaling, neurotransmitters are released into a space that is referred to as a

What property defines most ligands for intracellular receptors?

What kind of signaling molecule is MAPK? Many receptor tyrosine kinase pathways have MAPK as a downstream signaling component. MAPK can phosphorylate target proteins. What type of signaling molecule is MAPK?

Identifying the link between components in a signaling pathway: Your research project involves the characterization of a particular signal transduction pathway. Specifically, you have been studying a receptor tyrosine kinase and protein X, which initiates downstream events. You are certain that protein X is part of the signal transduction pathway, but have been unable to identify a direct protein-protein interaction between the receptor tyrosine kinase and the protein X. What should you do next in your attempt to identify a link between the receptor tyrosine kinase and protein X?

What kind of signaling molecule is Ste5? Ste5 binds to MAPKKK, MAPKK, and MAPK to organize the kinase cascade. What type of signaling molecule is Ste5?

If Ras and SOS cannot interact, what would be the effect on signaling? The protein SOS is a guanine nucleotide exchange factor for Ras. SOS helps facilitate the exchange of GDP for GTP. What would be the effect of a mutation that inhibits the interaction between SOS and Ras?

Large intracellular response due to activation of kinase cascades is referred to as what? A small number of cell surface receptors can ultimately generate a large intracellular response due to activation of kinase cascades. This is referred to as:

Effect of calcium not being able to bind to calmodulin: Calmodulin is a calcium-binding protein. A mutation that affects Ca++ binding to calmodulin is most likely to interfere with what aspect of a signal transduction pathway?