Cyclic guanosine monophosphate (cGMP) is a second messenger derived from GTP.

Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP, most notably by activating intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface. Image File history File links CGMP.png Cyclic guanosine monophosphate Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File links CGMP.png Cyclic guanosine monophosphate Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay a signal within a cell. ... Guanosine triphosphate (GTP) is also known as guanosine-5-triphosphate. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... Guanosine triphosphate (GTP) is also known as guanosine-5-triphosphate. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay a signal within a cell. ... Structure of cAMP Cyclic adenosine monophosphate (cAMP, cyclic AMP or 3-5-cyclic adenosine monophosphate) is a molecule that is important in many biological processes; it is derived from adenosine triphosphate (ATP). ... A protein kinase is an enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). ... It has been suggested that Net flux be merged into this article or section. ... Peptides (from the Greek πεπτος, digestible), are the family of molecules formed from the linking, in a defined order, of various amino acids. ... A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ...

Synthesis

cGMP synthesis is catalyzed by guanylate cyclase (GC), which converts GTP to cGMP. Membrane-bound GC is activated by peptide hormones such as the natriuretic factors, while nitric oxide typically stimulates cGMP synthesis in soluble GC. A catalyst (Greek: καταλύτης, catalytēs) is a substance that accelerates the rate (speed) of a chemical reaction (see also catalysis). ... Guanylate cyclase (EC 4. ... GTP (also known as guanylyl imidodiphosphate, guanosine-5-triphosphate, or guanosine triphosphate) is a chemical compound (nucleotide) that is incorporated into the growing RNA chain during synthesis of RNA and used as a source of energy during synthesis of proteins. ... The chemical compound nitric oxide is a gas with chemical formula NO. It is an important signaling molecule in the body of mammals including humans, one of the few gaseous signaling molecules known. ...

Effects

cGMP is a common regulator of ion channel conductance, glycogenolysis, and cellular apoptosis. It also relaxes smooth muscle tissues. In blood vessels, relaxation of vascular smooth muscles lead to vasodilation and increased blood flow. Another, unrelated ion channeling process is part of ion implantation. ... Conductance can refer to: Electrical conductance, the reciprocal of electrical resistance. ... Glycogenolysis is the catabolism of glycogen (requiring removal of glucose unit from glycogen and addition of phosphate) thus producing glucose 1-phosphate, and subsequently reconfigured (C-1 -> C-6) to yield glucose 6-phosphate, a potent reaction intermediary leading to glucose available to the blood and brain, pyruvic acid (yet... Apoptosis In biology, apoptosis (from the Greek words apo = from and ptosis = falling, commonly pronounced ap-a-tow-sis[1]) is one of the main types of programmed cell death (PCD). ... Smooth muscle is a type of non-striated muscle, found within the walls of hollow organs; such as blood vessels, bladders, uteri. ... The arterial system The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... A vasodilator is a substance that causes blood vessels in the body to become wider by relaxing the smooth muscle in the vessel wall, or vasodilation. ... Blood flow is the flow of blood in the cardiovascular system. ...

Degradation

Cyclic nucleotide phosphodiesterases (PDE 1-6) degrade cGMP by hydrolyzing cGMP into 5'-GMP. Diagram of phosphodiester bonds between nucleotides A phosphodiester bond is a group of strong covalent bonds between the phosphorus atom in a phosphate group and two other molecules over two ester bonds. ... Hydrolysis is a chemical process in which a molecule is split into two parts by the addition of a molecule of water. ...

Phosphodiesterase inhibitors prevent the degradation of cGMP, thereby enhancing and/or prolonging its effects. For example, Sildenafil (Viagra) enhances the vasodilatory effects of cGMP within the corpus cavernosum by inhibiting PDE 5 (or PDE V). This is used as a treatment for erectile dysfunction. A phosphodiesterase inhibitor is a drug that blocks one or more of the five subtypes of the enzyme phosphodiesterase (PDE), preventing the inactivation of the intracellular second messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). ... Sildenafil citrate, sold under the names Viagra, Revatio and (in the Indian subcontinent) Caverta, is a drug used to treat male erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH), developed by the pharmaceutical company Pfizer. ... A corpus cavernosum is one of a pair of a sponge-like regions of erectile tissue which contain most of the blood in the male penis during erection. ... Erectile dysfunction, also known as impotence, is a sexual dysfunction characterized by the inability to develop or maintain an erection of the penis for satisfactory sexual intercourse regardless of the capability of ejaculation. ...

Protein kinase activation

cGMP is involved in the regulation of some protein-dependent kinases. For example, PKG (protein kinase G) is a dimer consisting of one catalytic and one regulatory unit, with the regulatory units blocking the active sites of the catalytic units. Protein Kinase G (PKG) is enzyme that catalyzes the transfer of phosphate from ATP? to hydroxyl side chains on proteins, causing changes in function. ... Sucrose, or common table sugar, is composed of glucose and fructose. ... Generic graph showing the effect of a catalyst in an hypotetical exothermic chemical reaction. ... The active site of an enzyme is the binding site where catalysis occurs. ...

cGMP binds to sites on the regulatory units of PKG and activates the catalytic units, enabling them to phosphorylate their substrates. Unlike with the activation of some other protein kinases, notably PKA, the PKG is activated but the catalytic and regulatory units do not disassociate.

References

• Francis SH, Corbin JD. "Cyclic nucleotide-dependent protein kinases: intracellular receptors for cAMP and cGMP action." Crit Rev Clin Lab Sci. 1999 Aug;36(4):275-328. PMID 10486703

See also

• Cyclic adenosine monophosphate (cAMP)