Which enzyme is responsible for converting ATP to cAMP?

Adenylyl cyclase is the enzyme that catalyzes the conversion of ATP to cyclic AMP (cAMP). This process is a critical step in many signal transduction pathways within cells. When certain hormones or neurotransmitters bind to their respective receptors on the cell surface, they activate adenylyl cyclase through G protein-coupled receptor mechanisms. The increase in cAMP within the cell acts as a secondary messenger, activating various signaling pathways that can lead to diverse physiological effects, such as changes in metabolism, gene expression, and cell growth.

Phospholipase C is involved in a different signaling pathway where it generates inositol trisphosphate and diacylglycerol from membrane phospholipids, leading to the release of calcium ions and activation of protein kinase C. Protein kinase A is dependent on cAMP for its activity, as it is activated by cAMP but is not responsible for its production. Guanylate cyclase, in contrast, is responsible for converting GTP into cyclic GMP (cGMP), which is a separate signaling molecule with distinct pathways and effects within the cell.

This understanding of adenylyl cyclase's role in cAMP production is pivotal in physiology, particularly in