How does an increase in cAMP typically affect cellular activity?

How does an increase in cAMP typically affect cellular activity?

• A. Increases protein synthesis
• B. Inhibits cellular responses
• C. Activates protein kinase A (PKA)
• D. Decreases transporter activity

Answer: (C)

An increase in cyclic adenosine monophosphate (cAMP) primarily leads to the activation of protein kinase A (PKA). When cAMP levels rise in response to a signaling molecule, it binds to the regulatory subunits of PKA, causing a conformational change that releases the active catalytic subunits. These subunits can then phosphorylate various target proteins within the cell, which can lead to a wide range of cellular responses such as increased metabolic activity, regulation of gene expression, and other signaling pathways. This mechanism illustrates the role of cAMP as a second messenger in signaling pathways, where its primary function is to relay the signal from extracellular hormones to intracellular processes by activating various kinases, thereby promoting diverse cellular activities. The ability of cAMP to influence PKA activity is crucial for the modulation of metabolic pathways, cell growth, and differentiation, aligning with its role in amplifying the original signal received by the cell.

An increase in cyclic adenosine monophosphate (cAMP) primarily leads to the activation of protein kinase A (PKA). When cAMP levels rise in response to a signaling molecule, it binds to the regulatory subunits of PKA, causing a conformational change that releases the active catalytic subunits. These subunits can then phosphorylate various target proteins within the cell, which can lead to a wide range of cellular responses such as increased metabolic activity, regulation of gene expression, and other signaling pathways.

This mechanism illustrates the role of cAMP as a second messenger in signaling pathways, where its primary function is to relay the signal from extracellular hormones to intracellular processes by activating various kinases, thereby promoting diverse cellular activities. The ability of cAMP to influence PKA activity is crucial for the modulation of metabolic pathways, cell growth, and differentiation, aligning with its role in amplifying the original signal received by the cell.