GNAT2 explained

Guanine nucleotide-binding protein G(t) subunit alpha-2 is a protein that in humans is encoded by the GNAT2 gene.^{[1] [2]}

Function

Transducin is a 3-subunit guanine nucleotide-binding protein (G protein) which stimulates the coupling of rhodopsin and cGMP-phosphodiesterase during visual impulses. The transducin alpha subunits in rods and cones are encoded by separate genes. This gene encodes the alpha subunit in cones.

Further reading

• Wilkie TM, Gilbert DJ, Olsen AS . Evolution of the mammalian G protein alpha subunit multigene family . Nat. Genet. . 1 . 2 . 85–91 . 1993 . 1302014 . 10.1038/ng0592-85 . 31888533 . etal.
• Arshavsky VYu . Gray-Keller MP . Bownds MD . cGMP suppresses GTPase activity of a portion of transducin equimolar to phosphodiesterase in frog rod outer segments. Light-induced cGMP decreases as a putative feedback mechanism of the photoresponse . J. Biol. Chem. . 266 . 28 . 18530–7 . 1991 . 10.1016/S0021-9258(18)55094-8 . 1655754 . free .
• Mazzoni MR, Malinski JA, Hamm HE . Structural analysis of rod GTP-binding protein, Gt. Limited proteolytic digestion pattern of Gt with four proteases defines monoclonal antibody epitope . J. Biol. Chem. . 266 . 21 . 14072–81 . 1991 . 10.1016/S0021-9258(18)92811-5 . 1713215 . free .
• Fawzi AB, Fay DS, Murphy EA . Rhodopsin and the retinal G-protein distinguish among G-protein beta gamma subunit forms . J. Biol. Chem. . 266 . 19 . 12194–200 . 1991 . 10.1016/S0021-9258(18)98880-0 . 1905716 . etal. free .
• Kubo M, Hirano T, Kakinuma M . Molecular cloning and sequence analysis of cDNA and genomic DNA for the human cone transducin alpha subunit . FEBS Lett. . 291 . 2 . 245–8 . 1991 . 1936270 . 10.1016/0014-5793(91)81294-I . 84445060 .
• Lerea CL, Bunt-Milam AH, Hurley JB . Alpha transducin is present in blue-, green-, and red-sensitive cone photoreceptors in the human retina . Neuron . 3 . 3 . 367–76 . 1990 . 2534964 . 10.1016/0896-6273(89)90261-4 . 2870440 .
• Blatt C, Eversole-Cire P, Cohn VH . Chromosomal localization of genes encoding guanine nucleotide-binding protein subunits in mouse and human . Proc. Natl. Acad. Sci. U.S.A. . 85 . 20 . 7642–6 . 1988 . 2902634 . 10.1073/pnas.85.20.7642 . 282248 . 1988PNAS...85.7642B . etal. free .
• Buss JE, Mumby SM, Casey PJ . Myristoylated alpha subunits of guanine nucleotide-binding regulatory proteins . Proc. Natl. Acad. Sci. U.S.A. . 84 . 21 . 7493–7 . 1987 . 3118369 . 10.1073/pnas.84.21.7493 . 299322 . 1987PNAS...84.7493B . etal. free .
• Hirano T . [Analysis of cell specific transcription of the human cone transducin alpha subunit gene] . Hokkaido Igaku Zasshi . 68 . 6 . 885–93 . 1994 . 8112713 .
• Morris TA, Fong WB, Ward MJ . Localization of upstream silencer elements involved in the expression of cone transducin alpha-subunit (GNAT2) . Invest. Ophthalmol. Vis. Sci. . 38 . 1 . 196–206 . 1997 . 9008644 . etal.
• Kohl S, Baumann B, Rosenberg T . Mutations in the cone photoreceptor G-protein alpha-subunit gene GNAT2 in patients with achromatopsia . Am. J. Hum. Genet. . 71 . 2 . 422–5 . 2002 . 12077706 . 10.1086/341835 . 379175 . etal.
• Aligianis IA, Forshew T, Johnson S . Mapping of a novel locus for achromatopsia (ACHM4) to 1p and identification of a germline mutation in the alpha subunit of cone transducin (GNAT2) . J. Med. Genet. . 39 . 9 . 656–60 . 2002 . 12205108 . 10.1136/jmg.39.9.656 . 1735242 . etal.
• Strausberg RL, Feingold EA, Grouse LH . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . etal. free .
• Piña AL, Baumert U, Loyer M, Koenekoop RK . A three base pair deletion encoding the amino acid (lysine-270) in the alpha-cone transducin gene . Mol. Vis. . 10 . 265–71 . 2004 . 15094710 .
• Gerhard DS, Wagner L, Feingold EA . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . etal.
• Rosenberg T, Baumann B, Kohl S . Variant phenotypes of incomplete achromatopsia in two cousins with GNAT2 gene mutations . Invest. Ophthalmol. Vis. Sci. . 45 . 12 . 4256–62 . 2005 . 15557429 . 10.1167/iovs.04-0317 . etal. free .

External links

• GeneReviews/NIH/NCBI/UW entry on Achromatopsia
• OMIM entries on Achromatopsia

Notes and References

1. Morris TA, Fong SL . Characterization of the gene encoding human cone transducin alpha-subunit (GNAT2) . Genomics . 17 . 2 . 442–8 . Oct 1993 . 8406495 . 10.1006/geno.1993.1345 .
2. Web site: Entrez Gene: GNAT2 guanine nucleotide binding protein (G protein), alpha transducing activity polypeptide 2.