Cyclic AMP

Cyclic AMP (cAMP) is a derivative of adenosine triphosphate and is the first identified second messenger that transmits signals from receptors to downstream pathways^[1]. As an important intracellular signaling molecule, cyclic AMP participates in many biological processes, such as metabolic regulation, protein kinase activation, gene transcription, etc.^{[2, 3]}. Cyclic AMP is produced from ATP by several adenylate cyclases and anchored in various locations inside the cell. These enzymes are regulated by G protein-coupled receptors ^[4]. Cyclic AMP is broken down into adenosine monophosphate (AMP) by phosphodiesterases ^[5]. Cyclic AMP is a hydrophilic small molecule that contains a phosphate group, has high polarity, and can form hydrogen bonds with water molecules ^[6].

References:
[1] Muthal A P, Kulkarni R, Kumar D, et al. Cyclic adenosine monophosphate: Recent and future perspectives on various diseases[J]. Journal of Applied Pharmaceutical Science, 2022, 12(3): 001-015.
[2] Rutter G A, da Silva Xavier G, Leclerc I. Roles of 5′-AMP-activated protein kinase (AMPK) in mammalian glucose homoeostasis[J]. Biochemical Journal, 2003, 375(1): 1-16.
[3] De Cesare D, Sassone-Corsi P. Transcriptional regulation by cyclic AMP-responsive factors[J]. 2000.
[4] Kuhn M. Molecular physiology of membrane guanylyl cyclase receptors[J]. Physiological reviews, 2016.
[5] Pyne N J, Furman B L. Cyclic nucleotide phosphodiesterases in pancreatic islets[J]. Diabetologia, 2003, 46: 1179-1189.
[6] Kato Y, Conn M M, Rebek J J. Water-soluble receptors for cyclic-AMP and their use for evaluating phosphate-guanidinium interactions[J]. Journal of the American Chemical Society, 1994, 116(8): 3279-3284.

环磷酸腺苷（Cyclic AMP; cAMP）是三磷酸腺苷的衍生物，是第一个被鉴定出的第二信使，将信号从受体传播到下游途径^[1]。Cyclic AMP作为细胞内重要信号分子，参与许多生物过程，例如：代谢调节、蛋白激酶的激活、基因转录等^{[2, 3]}。Cyclic AMP是由几种腺苷酸环化酶从ATP产生的，并锚定在细胞内部的各个位置，这些酶受G蛋白偶联受体的调节^[4]。Cyclic AMP被磷酸二酯酶催化分解为单磷酸腺苷（AMP)^[5]。Cyclic AMP是一种亲水性小分子，含有磷酸基，具有高极性，能够与水分子形成氢键^[6]。