Cyclic guanosine monophosphate

Cyclic guanosine monophosphate
Cyclic guanosine monophosphate
CAS number 7665-99-8 YesY
PubChem 24316
ChemSpider 22734 YesY
MeSH Cyclic+GMP
ChEBI CHEBI:16356 YesY
IUPHAR ligand 2347
Jmol-3D images Image 1
Molecular formula C10H12N5O7P
Molar mass 345.21 g mol−1
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP. Its most likely mechanism of action is activation of intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface.[1]



Guanylate cyclase (GC) catalyzes cGMP synthesis. This enzyme converts GTP to cGMP. In turn, peptide hormones such as the atrial natriuretic factor activate membrane-bound GC, while soluble GC is typically activated by nitric oxide to stimulate cGMP synthesis.


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.

cGMP is a secondary messenger in phototransduction in the eye. In the photoreceptors of the mammalian eye, the presence of light activates phosphodiesterase, which degrades cGMP. The sodium ion channels in photoreceptors are cGMP-gated, so degradation of cGMP causes sodium channels to close, which leads to the hyperpolarization of the photoreceptor's plasma membrane and ultimately to visual information being sent to the brain.[2] GMP and a number of its derivatives also have an umami taste.[3]

cGMP is also seen to mediate the switching on of the attraction of apical dendrites of pyramidal cells in cortical layer V towards semaphorin-3A (Sema3a).[4] Whereas the axons of pyramidal cells are repelled by Sema3a, the apical dendrites are attracted to it. The attraction is mediated by the increased levels of soluble guanylate cyclase (SGC) that are present in the apical dendrites. SGC generates cGMP, leading to a sequence of chemical activations that result in the attraction towards Sema3a. The absence of SGC in the axon causes the repulsion from Sema3a. This strategy ensures the structural polarization of pyramidal neurons and takes place in embryonic development.


Numerous cyclic nucleotide phosphodiesterases (PDE) can degrade cGMP by hydrolyzing cGMP into 5'-GMP. PDE 5, -6 and -9 are cGMP-specific while PDE1, -2, -3, -10 and -11 can hydrolyse both cAMP and cGMP.

Phosphodiesterase inhibitors prevent the degradation of cGMP, thereby enhancing and/or prolonging its effects. For example, Sildenafil (Viagra) and similar drugs enhance 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. However, the drug can inhibit PDE6 in retina (albeit with less affinity than PDE5). This has been shown to result in loss sensitivity but is unlikely to impair common visual tasks, except under conditions of reduced visibility when objects are already near visual threshold.[5] This effect is largely avoided by other PDE5 inhibitors, such as tadalafil.[6]

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.

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.


  1. ^ Francis SH, Corbin JD (August 1999). "Cyclic nucleotide-dependent protein kinases: intracellular receptors for cAMP and cGMP action". Crit Rev Clin Lab Sci 36 (4): 275–328. doi:10.1080/10408369991239213. ISSN 1040-8363. PMID 10486703. 
  2. ^ R. Lane Brown, Timothy Strassmaier, James D. Brady, Jeffrey W. Karpen (2006). "The Pharmacology of Cyclic Nucleotide-Gated Channels: Emerging from the Darkness". Current Pharmaceutical Design 12 (28): 3597–613. doi:10.2174/138161206778522100. PMC 2467446. PMID 17073662. NIHMSID: NIHMS47625. 
  3. ^ Cairoli P, Pieraccini S, Sironi M, Morelli CF, Speranza G, Manitto P (February 2008). "Studies on umami taste. Synthesis of new guanosine 5'-phosphate derivatives and their synergistic effect with monosodium glutamate". J. Agric. Food Chem. 56 (3): 1043–50. doi:10.1021/jf072803c. ISSN 0021-8561. PMID 18181569. 
  4. ^ Franck Polleux, Theresa Morrow, Anirvan Ghosh (April 2000). "Semaphorin 3A is a chemoattractant for cortical apical dendrites". Nature 404 (6778): 567–73. doi:10.1038/35007001. PMID 10766232. 
  5. ^ Stockman, A; Sharpe, LT; Tufail, A; Kell, PD; Ripamonti, C; Jeffery, G (June 2007). "The effect of sildenafil citrate (Viagra) on visual sensitivity" (Free full text). J Vis 7 (8): 4. doi:10.1167/7.8.4. PMID 17685811. 
  6. ^ Daugan, A; Grondin, P; Ruault, C; Le Monnier De Gouville, AC; Coste, H; Linget, JM; Kirilovsky, J; Hyafil, F et al. (October 2003). "The discovery of tadalafil: a novel and highly selective PDE5 inhibitor. 2: 2,3,6,7,12,12a-hexahydropyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione analogues". J Med Chem 46 (21): 4533–42. doi:10.1021/jm0300577. ISSN 0022-2623. PMID 14521415. 

See also

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • cyclic guanosine monophosphate — n CYCLIC GMP * * * a cyclic nucleotide, guanosine 3′,5′ cyclic monophosphate, an intracellular “second messenger” similar in action to cyclic adenosine monophosphate (q.v.); the two cyclic nucleotides activate different protein… …   Medical dictionary

  • cyclic guanosine monophosphate — ˌmänə¦fäsˌfāt, ˌmōn noun Etymology: mon + phosphate : cyclic GMP herein …   Useful english dictionary

  • Cyclic adenosine monophosphate — Identifiers …   Wikipedia

  • guanosine monophosphate — ˌmä(ˌ)nō, ˌmō(ˌ)nō, nəˌ noun Etymology: mon + phosphate : cyclic GMP herein * * * Biochem. See GMP. [MONO + PHOSPHATE] …   Useful english dictionary

  • Cyclic nucleotide-gated ion channel — Cyclic nucleotide gated (CNG) ion channels are ion channels that function in response to the binding of cyclic nucleotides. CNG channels are nonselective cation channels that are found in the membranes of various types of cells. Signal… …   Wikipedia

  • Di-guanosine monophosphate cyclique — Structure de la di guanosine monophosphate cyclique Général Synonymes …   Wikipédia en Français

  • Cyclic nucleotide — Cyclic adenosine monophosphate …   Wikipedia

  • cyclic GMP — SYN: cyclic guanosine 3′,5′ monophosphate. * * * cyclic GMP .jē .em pē n a cyclic mononucleotide of guanosine that acts similarly to cyclic AMP as a second messenger in response to hormones called also cyclic guanosine monophosphate, guanosine 3 …   Medical dictionary

  • Guanosine — chembox ImageFile=G chemical structure.png ImageSize= IUPACName= OtherNames= Section1= Chembox Identifiers CASNo=118 00 3 PubChem=765 SMILES=NC1=Nc2 [n] (cnc2C(=O)N1) [C@@H] 3O [C@H] (CO)C(O)C3O MeSHName=Guanosine Section2= Chembox Properties… …   Wikipedia

  • Guanosine triphosphate — IUPAC name [(2R,3S,4R,5R) 5 (2 amino 6 oxo 3H purin …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”