Abstract
Recent molecular cloning of cDNA for the alpha subunit of bovine transducin (a guanine nucleotide-binding regulatory protein, or G protein) has revealed the presence of two retinal-specific transducins, called Tr and Tc, which are expressed in rod or cone photoreceptor cells. In a further study of G-protein diversity and signal transduction in the retina, we have identified a G-protein alpha subunit, which we refer to as Gz alpha, by isolating a human retinal cDNA clone that cross-hybridizes at reduced stringency with bovine Tr alpha-subunit cDNA. The deduced amino acid sequence of Gz alpha is 41-67% identical with those of other known G-protein alpha subunits. However, the 355-residue Gz alpha lacks a consensus site for ADP-ribosylation by pertussis toxin, and its amino acid sequence varies within a number of regions that are strongly conserved among all of the other G-protein alpha subunits. We suggest that Gz alpha, which appears to be highly expressed in neural tissues, represents a member of a subfamily of G proteins that mediate signal transduction in pertussis toxin-insensitive systems.
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- Aub D. L., Frey E. A., Sekura R. D., Cote T. E. Coupling of the thyrotropin-releasing hormone receptor to phospholipase C by a GTP-binding protein distinct from the inhibitory or stimulatory GTP-binding protein. J Biol Chem. 1986 Jul 15;261(20):9333–9340. [PubMed] [Google Scholar]
- Barbacid M. ras genes. Annu Rev Biochem. 1987;56:779–827. doi: 10.1146/annurev.bi.56.070187.004023. [DOI] [PubMed] [Google Scholar]
- Blin N., Stafford D. W. A general method for isolation of high molecular weight DNA from eukaryotes. Nucleic Acids Res. 1976 Sep;3(9):2303–2308. doi: 10.1093/nar/3.9.2303. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dever T. E., Glynias M. J., Merrick W. C. GTP-binding domain: three consensus sequence elements with distinct spacing. Proc Natl Acad Sci U S A. 1987 Apr;84(7):1814–1818. doi: 10.1073/pnas.84.7.1814. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Didsbury J. R., Ho Y. S., Snyderman R. Human Gi protein alpha-subunit: deduction of amino acid structure from a cloned cDNA. FEBS Lett. 1987 Jan 26;211(2):160–164. doi: 10.1016/0014-5793(87)81428-x. [DOI] [PubMed] [Google Scholar]
- Evans T., Fawzi A., Fraser E. D., Brown M. L., Northup J. K. Purification of a beta 35 form of the beta gamma complex common to G-proteins from human placental membranes. J Biol Chem. 1987 Jan 5;262(1):176–181. [PubMed] [Google Scholar]
- Fong H. K., Amatruda T. T., 3rd, Birren B. W., Simon M. I. Distinct forms of the beta subunit of GTP-binding regulatory proteins identified by molecular cloning. Proc Natl Acad Sci U S A. 1987 Jun;84(11):3792–3796. doi: 10.1073/pnas.84.11.3792. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gao B., Gilman A. G., Robishaw J. D. A second form of the beta subunit of signal-transducing G proteins. Proc Natl Acad Sci U S A. 1987 Sep;84(17):6122–6125. doi: 10.1073/pnas.84.17.6122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilman A. G. G proteins: transducers of receptor-generated signals. Annu Rev Biochem. 1987;56:615–649. doi: 10.1146/annurev.bi.56.070187.003151. [DOI] [PubMed] [Google Scholar]
- Halliday K. R. Regional homology in GTP-binding proto-oncogene products and elongation factors. J Cyclic Nucleotide Protein Phosphor Res. 1983;9(6):435–448. [PubMed] [Google Scholar]
- Hildebrandt J. D., Codina J., Rosenthal W., Birnbaumer L., Neer E. J., Yamazaki A., Bitensky M. W. Characterization by two-dimensional peptide mapping of the gamma subunits of Ns and Ni, the regulatory proteins of adenylyl cyclase, and of transducin, the guanine nucleotide-binding protein of rod outer segments of the eye. J Biol Chem. 1985 Nov 25;260(27):14867–14872. [PubMed] [Google Scholar]
- Jones D. T., Reed R. R. Molecular cloning of five GTP-binding protein cDNA species from rat olfactory neuroepithelium. J Biol Chem. 1987 Oct 15;262(29):14241–14249. [PubMed] [Google Scholar]
- Lerea C. L., Somers D. E., Hurley J. B., Klock I. B., Bunt-Milam A. H. Identification of specific transducin alpha subunits in retinal rod and cone photoreceptors. Science. 1986 Oct 3;234(4772):77–80. doi: 10.1126/science.3529395. [DOI] [PubMed] [Google Scholar]
- Lipman D. J., Pearson W. R. Rapid and sensitive protein similarity searches. Science. 1985 Mar 22;227(4693):1435–1441. doi: 10.1126/science.2983426. [DOI] [PubMed] [Google Scholar]
- Martin M. W., Evans T., Harden T. K. Further evidence that muscarinic cholinergic receptors of 1321N1 astrocytoma cells couple to a guanine nucleotide regulatory protein that is not Ni. Biochem J. 1985 Jul 15;229(2):539–544. doi: 10.1042/bj2290539. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martin T. F., Lucas D. O., Bajjalieh S. M., Kowalchyk J. A. Thyrotropin-releasing hormone activates a Ca2+-dependent polyphosphoinositide phosphodiesterase in permeable GH3 cells. GTP gamma S potentiation by a cholera and pertussis toxin-insensitive mechanism. J Biol Chem. 1986 Feb 25;261(6):2918–2927. [PubMed] [Google Scholar]
- Masters S. B., Martin M. W., Harden T. K., Brown J. H. Pertussis toxin does not inhibit muscarinic-receptor-mediated phosphoinositide hydrolysis or calcium mobilization. Biochem J. 1985 May 1;227(3):933–937. doi: 10.1042/bj2270933. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Masters S. B., Stroud R. M., Bourne H. R. Family of G protein alpha chains: amphipathic analysis and predicted structure of functional domains. Protein Eng. 1986 Oct-Nov;1(1):47–54. [PubMed] [Google Scholar]
- Mattera R., Codina J., Crozat A., Kidd V., Woo S. L., Birnbaumer L. Identification by molecular cloning of two forms of the alpha-subunit of the human liver stimulatory (GS) regulatory component of adenylyl cyclase. FEBS Lett. 1986 Sep 29;206(1):36–42. doi: 10.1016/0014-5793(86)81336-9. [DOI] [PubMed] [Google Scholar]
- Möller W., Amons R. Phosphate-binding sequences in nucleotide-binding proteins. FEBS Lett. 1985 Jul 1;186(1):1–7. doi: 10.1016/0014-5793(85)81326-0. [DOI] [PubMed] [Google Scholar]
- Roof D. J., Applebury M. L., Sternweis P. C. Relationships within the family of GTP-binding proteins isolated from bovine central nervous system. J Biol Chem. 1985 Dec 25;260(30):16242–16249. [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stryer L., Bourne H. R. G proteins: a family of signal transducers. Annu Rev Cell Biol. 1986;2:391–419. doi: 10.1146/annurev.cb.02.110186.002135. [DOI] [PubMed] [Google Scholar]
- Stryer L. Cyclic GMP cascade of vision. Annu Rev Neurosci. 1986;9:87–119. doi: 10.1146/annurev.ne.09.030186.000511. [DOI] [PubMed] [Google Scholar]
- Uhing R. J., Prpic V., Jiang H., Exton J. H. Hormone-stimulated polyphosphoinositide breakdown in rat liver plasma membranes. Roles of guanine nucleotides and calcium. J Biol Chem. 1986 Feb 15;261(5):2140–2146. [PubMed] [Google Scholar]
- Van Dop C., Tsubokawa M., Bourne H. R., Ramachandran J. Amino acid sequence of retinal transducin at the site ADP-ribosylated by cholera toxin. J Biol Chem. 1984 Jan 25;259(2):696–698. [PubMed] [Google Scholar]
- West R. E., Jr, Moss J., Vaughan M., Liu T., Liu T. Y. Pertussis toxin-catalyzed ADP-ribosylation of transducin. Cysteine 347 is the ADP-ribose acceptor site. J Biol Chem. 1985 Nov 25;260(27):14428–14430. [PubMed] [Google Scholar]