Abstract
Diversity of gamma-aminobutyrate type A (GABAA) receptors has recently been proposed to be achieved by assembly of receptor subtypes from a multitude of subunits (alpha 1-6, beta 1-3, gamma 1-2, and delta) encoded by different genes. Here we report a further mechanism for creating GABAA receptor diversity: alternative RNA splicing. Two forms of bovine gamma 2 subunit cDNA were isolated (gamma 2S and gamma 2L) that differed by the presence or absence of a 24-base-pair (8-amino acid) insertion in the cytoplasmic domain between the third and fourth putative membrane-spanning regions. Polymerase chain reaction from RNA demonstrated that the two forms of gamma 2 subunit are expressed in bovine, human, and rat brain. Sequencing of genomic DNA clones encoding the gamma 2 subunit demonstrated that the 24-base-pair insert is organized as a separate exon. Analysis of the sequence of the 8-amino acid insert revealed that it contains a protein kinase C consensus phosphorylation site. Expression of the large cytoplasmic loop domains of gamma 2S and gamma 2L in Escherichia coli, followed by phosphorylation of the recombinant proteins by protein kinase C, demonstrated that gamma 2L, but not gamma 2S, could be phosphorylated. Thus the two forms of gamma 2 subunit differ by the presence or absence of a protein kinase C phosphorylation site. This mechanism for creating GABAA receptor diversity may allow differential regulation of the function of receptor subtypes.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Beeson D., Morris A., Vincent A., Newsom-Davis J. The human muscle nicotinic acetylcholine receptor alpha-subunit exist as two isoforms: a novel exon. EMBO J. 1990 Jul;9(7):2101–2106. doi: 10.1002/j.1460-2075.1990.tb07378.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Browning M. D., Bureau M., Dudek E. M., Olsen R. W. Protein kinase C and cAMP-dependent protein kinase phosphorylate the beta subunit of the purified gamma-aminobutyric acid A receptor. Proc Natl Acad Sci U S A. 1990 Feb;87(4):1315–1318. doi: 10.1073/pnas.87.4.1315. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chio C. L., Hess G. F., Graham R. S., Huff R. M. A second molecular form of D2 dopamine receptor in rat and bovine caudate nucleus. Nature. 1990 Jan 18;343(6255):266–269. doi: 10.1038/343266a0. [DOI] [PubMed] [Google Scholar]
- Dal Toso R., Sommer B., Ewert M., Herb A., Pritchett D. B., Bach A., Shivers B. D., Seeburg P. H. The dopamine D2 receptor: two molecular forms generated by alternative splicing. EMBO J. 1989 Dec 20;8(13):4025–4034. doi: 10.1002/j.1460-2075.1989.tb08585.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Diehl R. E., Whiting P., Potter J., Gee N., Ragan C. I., Linemeyer D., Schoepfer R., Bennett C., Dixon R. A. Cloning and expression of bovine brain inositol monophosphatase. J Biol Chem. 1990 Apr 15;265(11):5946–5949. [PubMed] [Google Scholar]
- Eusebi F., Molinaro M., Zani B. M. Agents that activate protein kinase C reduce acetylcholine sensitivity in cultured myotubes. J Cell Biol. 1985 Apr;100(4):1339–1342. doi: 10.1083/jcb.100.4.1339. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Giros B., Sokoloff P., Martres M. P., Riou J. F., Emorine L. J., Schwartz J. C. Alternative splicing directs the expression of two D2 dopamine receptor isoforms. Nature. 1989 Dec 21;342(6252):923–926. doi: 10.1038/342923a0. [DOI] [PubMed] [Google Scholar]
- Hemmings H. C., Jr, Nairn A. C., McGuinness T. L., Huganir R. L., Greengard P. Role of protein phosphorylation in neuronal signal transduction. FASEB J. 1989 Mar;3(5):1583–1592. doi: 10.1096/fasebj.3.5.2493406. [DOI] [PubMed] [Google Scholar]
- Khrestchatisky M., MacLennan A. J., Chiang M. Y., Xu W. T., Jackson M. B., Brecha N., Sternini C., Olsen R. W., Tobin A. J. A novel alpha subunit in rat brain GABAA receptors. Neuron. 1989 Dec;3(6):745–753. doi: 10.1016/0896-6273(89)90243-2. [DOI] [PubMed] [Google Scholar]
- Levitan E. S., Schofield P. R., Burt D. R., Rhee L. M., Wisden W., Köhler M., Fujita N., Rodriguez H. F., Stephenson A., Darlison M. G. Structural and functional basis for GABAA receptor heterogeneity. Nature. 1988 Sep 1;335(6185):76–79. doi: 10.1038/335076a0. [DOI] [PubMed] [Google Scholar]
- Lippa A. S., Garrett K. M., Tabakoff B., Beer B., Wennogle L. P., Meyerson L. R. Heterogeneity of brain benzodiazepine receptors: effects of physiological conditions. Brain Res Bull. 1985 Feb;14(2):189–195. doi: 10.1016/0361-9230(85)90078-4. [DOI] [PubMed] [Google Scholar]
- Lüddens H., Pritchett D. B., Köhler M., Killisch I., Keinänen K., Monyer H., Sprengel R., Seeburg P. H. Cerebellar GABAA receptor selective for a behavioural alcohol antagonist. Nature. 1990 Aug 16;346(6285):648–651. doi: 10.1038/346648a0. [DOI] [PubMed] [Google Scholar]
- Malherbe P., Sigel E., Baur R., Persohn E., Richards J. G., Möhler H. Functional expression and sites of gene transcription of a novel alpha subunit of the GABAA receptor in rat brain. FEBS Lett. 1990 Jan 29;260(2):261–265. doi: 10.1016/0014-5793(90)80118-3. [DOI] [PubMed] [Google Scholar]
- Monsma F. J., Jr, McVittie L. D., Gerfen C. R., Mahan L. C., Sibley D. R. Multiple D2 dopamine receptors produced by alternative RNA splicing. Nature. 1989 Dec 21;342(6252):926–929. doi: 10.1038/342926a0. [DOI] [PubMed] [Google Scholar]
- Moran O., Dascal N. Protein kinase C modulates neurotransmitter responses in Xenopus oocytes injected with rat brain RNA. Brain Res Mol Brain Res. 1989 May;5(3):193–202. doi: 10.1016/0169-328x(89)90035-1. [DOI] [PubMed] [Google Scholar]
- Nef P., Mauron A., Stalder R., Alliod C., Ballivet M. Structure linkage, and sequence of the two genes encoding the delta and gamma subunits of the nicotinic acetylcholine receptor. Proc Natl Acad Sci U S A. 1984 Dec;81(24):7975–7979. doi: 10.1073/pnas.81.24.7975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pritchett D. B., Lüddens H., Seeburg P. H. Type I and type II GABAA-benzodiazepine receptors produced in transfected cells. Science. 1989 Sep 22;245(4924):1389–1392. doi: 10.1126/science.2551039. [DOI] [PubMed] [Google Scholar]
- Pritchett D. B., Seeburg P. H. Gamma-aminobutyric acidA receptor alpha 5-subunit creates novel type II benzodiazepine receptor pharmacology. J Neurochem. 1990 May;54(5):1802–1804. doi: 10.1111/j.1471-4159.1990.tb01237.x. [DOI] [PubMed] [Google Scholar]
- Pritchett D. B., Sontheimer H., Gorman C. M., Kettenmann H., Seeburg P. H., Schofield P. R. Transient expression shows ligand gating and allosteric potentiation of GABAA receptor subunits. Science. 1988 Dec 2;242(4883):1306–1308. doi: 10.1126/science.2848320. [DOI] [PubMed] [Google Scholar]
- Pritchett D. B., Sontheimer H., Shivers B. D., Ymer S., Kettenmann H., Schofield P. R., Seeburg P. H. Importance of a novel GABAA receptor subunit for benzodiazepine pharmacology. Nature. 1989 Apr 13;338(6216):582–585. doi: 10.1038/338582a0. [DOI] [PubMed] [Google Scholar]
- Rosenberg A. H., Lade B. N., Chui D. S., Lin S. W., Dunn J. J., Studier F. W. Vectors for selective expression of cloned DNAs by T7 RNA polymerase. Gene. 1987;56(1):125–135. doi: 10.1016/0378-1119(87)90165-x. [DOI] [PubMed] [Google Scholar]
- Safran A., Sagi-Eisenberg R., Neumann D., Fuchs S. Phosphorylation of the acetylcholine receptor by protein kinase C and identification of the phosphorylation site within the receptor delta subunit. J Biol Chem. 1987 Aug 5;262(22):10506–10510. [PubMed] [Google Scholar]
- Schofield P. R., Darlison M. G., Fujita N., Burt D. R., Stephenson F. A., Rodriguez H., Rhee L. M., Ramachandran J., Reale V., Glencorse T. A. Sequence and functional expression of the GABA A receptor shows a ligand-gated receptor super-family. Nature. 1987 Jul 16;328(6127):221–227. doi: 10.1038/328221a0. [DOI] [PubMed] [Google Scholar]
- Shapiro M. B., Senapathy P. RNA splice junctions of different classes of eukaryotes: sequence statistics and functional implications in gene expression. Nucleic Acids Res. 1987 Sep 11;15(17):7155–7174. doi: 10.1093/nar/15.17.7155. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shivers B. D., Killisch I., Sprengel R., Sontheimer H., Köhler M., Schofield P. R., Seeburg P. H. Two novel GABAA receptor subunits exist in distinct neuronal subpopulations. Neuron. 1989 Sep;3(3):327–337. doi: 10.1016/0896-6273(89)90257-2. [DOI] [PubMed] [Google Scholar]
- Squires R. F., Benson D. I., Braestrup C., Coupet J., Klepner C. A., Myers V., Beer B. Some properties of brain specific benzodiazepine receptors: new evidence for multiple receptors. Pharmacol Biochem Behav. 1979 May;10(5):825–830. doi: 10.1016/0091-3057(79)90341-1. [DOI] [PubMed] [Google Scholar]
- Tsujino T., Kose A., Saito N., Tanaka C. Light and electron microscopic localization of beta I-, beta II-, and gamma-subspecies of protein kinase C in rat cerebral neocortex. J Neurosci. 1990 Mar;10(3):870–884. doi: 10.1523/JNEUROSCI.10-03-00870.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woodgett J. R., Gould K. L., Hunter T. Substrate specificity of protein kinase C. Use of synthetic peptides corresponding to physiological sites as probes for substrate recognition requirements. Eur J Biochem. 1986 Nov 17;161(1):177–184. doi: 10.1111/j.1432-1033.1986.tb10139.x. [DOI] [PubMed] [Google Scholar]
- Ymer S., Draguhn A., Köhler M., Schofield P. R., Seeburg P. H. Sequence and expression of a novel GABAA receptor alpha subunit. FEBS Lett. 1989 Nov 20;258(1):119–122. doi: 10.1016/0014-5793(89)81630-8. [DOI] [PubMed] [Google Scholar]
- Ymer S., Schofield P. R., Draguhn A., Werner P., Köhler M., Seeburg P. H. GABAA receptor beta subunit heterogeneity: functional expression of cloned cDNAs. EMBO J. 1989 Jun;8(6):1665–1670. doi: 10.1002/j.1460-2075.1989.tb03557.x. [DOI] [PMC free article] [PubMed] [Google Scholar]