Question
Beta 2 receptors act via following secondary messenger
| A. |
Adenylate Cyclase
|
| B. |
Tyrosine kinase receptors
|
| C. |
TGF-beta receptors
|
| D. |
Cytokine receptors
|
Show Answer
|
Correct Answer � A
Explanation
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|
– Beta-2 adrenergic receptors (β2 receptors) are G-protein coupled receptors (GPCRs) that activate the Gs protein.
– Activation of the Gs protein → adenylate cyclase activation.
– Adenylate cyclase ↑ conversion of ATP to cyclic AMP (cAMP).
– cAMP, a secondary messenger, activates protein kinase A (PKA), causing cellular effects.
Incorrect Options:
– Tyrosine kinase receptors: Involved in growth factor signaling, not β2 pathway.
– TGF-beta receptors: Serine/threonine kinase receptors; don’t interact with adenylate cyclase.
– Cytokine receptors: Typically activate the JAK-STAT pathway, not adenylate cyclase.
