cAMP and cGMP Signaling — Flashcards

Flashcard 1: In the adenylyl cyclase mechanism of cellular signaling, the _____ complex activates adenylyl cyclase, which then catalyzes the conversion of ATP to cAMP

Answer: Gαs-GTP

Flashcard 2: Gi proteins _____ the cAMP signaling cascade

Answer: inhibit

Flashcard 3: Once nitric oxide diffuses into muscle cells, it activates soluble (cytosolic) guanylyl cyclase, which converts _____ to cGMP

Answer: GTP

Flashcard 4: After its use as a second messenger in the adenylyl cyclase signaling pathway, cAMP is degraded to _____ by phosphodiesterase

Answer: 5'-AMP

Flashcard 5: Increased levels of cGMP cause _____ dephosphorylation, preventing its interaction with actin

Answer: myosin light chain

Flashcard 6: In the phospholipase C mechanism of cellular signaling, the _____ complex activates phospholipase C, which then catalyzes the liberation of DAG and IP3 from PIP2

Answer: q-GTP

Flashcard 7: Activation of a **GPCR** involves the exchange of _____ for _____ on the Gα subunit, leading to its dissociation from the Gβγ complex.

Answer: GDP

Extra: The Gα subunit possesses intrinsic GTPase activity, which hydrolyzes GTP back to GDP to terminate the signal. The GPCR itself acts as a Guanine nucleotide Exchange Factor (GEF) upon ligand binding.

Flashcard 8: Binding of atrial natriuretic peptide to its receptor guanylyl cyclase causes conversion of _____ to cGMP

Answer: GTP

Flashcard 9: Cyclin _____ and Cyclin E-CDK2 drive cells from G1 to S phase

Answer: D-CDK4/CDK6

Flashcard 10: _____ is the only known member of the CX3C chemokine group.

Answer: Fractalkine