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| Names | |
|---|---|
| Other names cGAMP; cyclic GMP-AMP; cGAMP(2'-5'); cyclic Gp(2'-5')Ap(3'-5') | |
| Identifiers | |
3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| KEGG | |
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| Properties | |
| C20H24N10O13P2 | |
| Molar mass | 674.417 g·mol−1 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Cyclic guanosine monophosphate–adenosine monophosphate (cyclic GMP-AMP, cGAMP) is the firstcyclic di-nucleotide found inmetazoa.[1] In mammalian cells, cGAMP is synthesized bycyclic GMP-AMP synthase (cGAS) fromATP andGTP upon cytosolic DNA stimulation.[2] cGAMP produced by cGAS contains mixed phosphodiester linkages, with one between 2'-OH of GMP and 5'-phosphate of AMP and the other between 3'-OH of AMP and 5'-phosphate of GMP.[3][4][5][6]
This molecule, referred to as 2′3′-cGAMP (cyclic [G(2’,5’)pA(3’,5’)p]), functions as an endogenoussecond messenger inducingSTING-dependenttype I interferon response.[1][3] cGAMP has also been shown to be an effective adjuvant that boosts the production of antigen-specific antibodies and T cell responses in mice.[7] cGAMP exercises antiviral functions in the cell where it is produced, but can also crosscell membranes bypassive diffusion through gap junctions to exert effects on neighboring cells.[8][9] It may even be packaged intolentivirus (such asHIV-1),poxvirus andherpes virus, and undercell culture conditions has been found to transmit an antiviral signal to the cells infected with these viruses; however, there is reason to think that at least HIV is capable of evading this mechanism by some means.[8][9]
In recent years, cGAMP signalling has been identified inprokaryotes includingVibrio cholerae which express a bacterial analogue of cGAS. In these organisms, cGAS is encoded as part of an operon alongside cGAMP-activated phospholipases (e.g. CapV inV. cholerae). During infection bybacteriophage, cGAS is activated and cGAMP is synthesised, activating CapV which degrades the cell's membrane and triggers cell death before the phage can complete its replicatory cycle.[10]
