What is the Origin of cAMP Signaling Pathway?

The discovery of cyclic AMP as a second messenger by Earl Sutherland in the late 1950s revolutionized the understanding of how hormones exert their effects without entering the cell, a finding for which he was awarded the Nobel Prize. The pathway's name is purely descriptive, referring to the cyclic structure of the adenosine monophosphate molecule that serves as the key intermediate signal.

What is the Mechanism of cAMP Signaling Pathway?

The process begins when a hydrophilic hormone, the first messenger, binds to a G protein-coupled receptor (GPCR) on the cell membrane. This binding activates the G protein, which in turn stimulates the enzyme adenylyl cyclase to convert ATP into cyclic AMP. Elevated cAMP then primarily activates Protein Kinase A (PKA), which phosphorylates various downstream target proteins and transcription factors, leading to diverse and specific cellular outcomes like glycogen breakdown or cortisol secretion.

cAMP Signaling Pathway

Meaning

The cyclic Adenosine Monophosphate (cAMP) signaling pathway is a ubiquitous intracellular cascade that acts as a second messenger system, relaying signals from numerous extracellular hormones to effect a cellular response. This pathway is a cornerstone of hydrophilic hormone action, enabling a rapid and amplified cellular response to an external stimulus. It is critical for regulating metabolism, gene expression, and cardiac function.