In studies trying to understand the regulation of hormone-sensitive adenylate cyclase, it was discovered that non-hydrolyzable GTP analogs and cholera toxin (that inhibits the GTPase activity of Gs ) were able to activate the enzyme in a sustained (irreversible) profile, therefore indicating that GTP hydrolysis represents a deactivation (turn-off) regulatory step. a) Will these analogs or toxin have any effect on adenylate cyclase activity in the absence of any added hormone? b) If you add an factor that increases the rate of GTPase hydrolysis of the Gs protein, will this activate or inhibit the observed downstream effect upon addition of the hormone (this is in the absence of GTP analogs or toxin). Explain your answer.

In studies trying to understand the regulation of hormone-sensitive adenylate cyclase, it was discovered that non-hydrolyzable GTP analogs and cholera toxin (that inhibits the GTPase activity of Gs ) were able to activate the enzyme in a sustained (irreversible) profile, therefore indicating that GTP hydrolysis represents a deactivation (turn-off) regulatory step. a) Will these analogs or toxin have any effect on adenylate cyclase activity in the absence of any added hormone? b) If you add an factor that increases the rate of GTPase hydrolysis of the Gs protein, will this activate or inhibit the observed downstream effect upon addition of the hormone (this is in the absence of GTP analogs or toxin). Explain your answer.

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Description: In studies trying to understand the regulation of hormone-sensitive adenylatecyclase, it was discovered that non-hydrolyzable GTP analogs and cholera toxin (that inhibits theGTPase activity of Gs ) were able to activate the enzyme in a sustained (irr

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter9: Cell Communication

Section9.4: Signaling Pathways Triggered By Internal Receptors

Problem 1SB: What distinguishes a steroid receptor from a receptor tyrosine kinase receptor or a...

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