What role does PKA (protein kinase A) play in gene regulation?

PKA (protein kinase A) plays a critical role in gene regulation through the process of phosphorylation. This enzyme is a serine/threonine kinase that adds phosphate groups to specific amino acids in target proteins, which can lead to changes in their activity, localization, or interactions with other molecules. Phosphorylation often serves as a regulatory mechanism; by modifying the structure and function of proteins, PKA can influence various cellular processes, including the regulation of gene expression.

In the context of gene regulation, PKA can activate or inactivate transcription factors that bind to DNA and control the transcription of specific genes. Therefore, by phosphorylating these transcription factors or other proteins involved in the transcription process, PKA directly influences the expression of specific genes.

The other options, while related to cellular processes, do not accurately capture the primary role of PKA in gene regulation. Protein synthesis and degradation involve different mechanisms and enzymes, while the activation of target genes is a downstream effect that can result from PKA's phosphorylation of regulatory proteins.