Adenylyl cyclase creates multiple cyclic AMP molecules, which fan out and activate protein kinases (PKA, in this example). Protein kinases can enter the nucleus and affect transcription.

A new study published in Biochemistry sheds light on how bacteria regulate their genes, challenging long-held assumptions ...

This increase of cyclic AMP leads to the activation of protein kinase A, which inhibits the phosphorylation of myosin and lowers intracellular ionic calcium concentrations, resulting in relaxation.

Upon binding to a ligand – which can range from small molecules like cyclic AMP to peptides and large proteins – GPCRs ... is a receptor tyrosine kinase essential for the differentiation ...