• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Oct 29, 1996; 93(22): 12278–12282.
PMCID: PMC37981

Novel Gq alpha isoform is a candidate transducer of rhodopsin signaling in a Drosophila testes-autonomous pacemaker.

Abstract

DGq is the alpha subunit of the heterotrimeric GTPase (G alpha), which couples rhodopsin to phospholipase C in Drosophila vision. We have uncovered three duplicated exons in dgq by scanning the GenBank data base for unrecognized coding sequences. These alternative exons encode sites involved in GTPase activity and G beta-binding, NorpA (phospholipase C)-binding, and rhodopsin-binding. We examined the in vivo splicing of dgq in adult flies and find that, in all but the male gonads, only two isoforms are expressed. One, dgqA, is the original visual isoform and is expressed in eyes, ocelli, brain, and male gonads. The other, dgqB, has the three novel exons and is widely expressed. Remarkably, all three nonvisual B exons are highly similar (82% identity at the amino acid level) to the Gq alpha family consensus, from Caenorhabditis elegans to human, but all three visual A exons are divergent (61% identity). Intriguingly, we have found a third isoform, dgqC, which is specifically and abundantly expressed in male gonads, and shares the divergent rhodopsin-binding exon of dgqA. We suggest that DGqC is a candidate for the light-signal transducer of a testes-autonomous photosensory clock. This proposal is supported by the finding that rhodopsin 2 and arrestin 1, two photoreceptor-cell-specific genes, are also expressed in male gonads.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.4M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Ranganathan R, Malicki DM, Zuker CS. Signal transduction in Drosophila photoreceptors. Annu Rev Neurosci. 1995;18:283–317. [PubMed]
  • Scott K, Becker A, Sun Y, Hardy R, Zuker C. Gq alpha protein function in vivo: genetic dissection of its role in photoreceptor cell physiology. Neuron. 1995 Oct;15(4):919–927. [PubMed]
  • Dolph PJ, Man-Son-Hing H, Yarfitz S, Colley NJ, Deer JR, Spencer M, Hurley JB, Zuker CS. An eye-specific G beta subunit essential for termination of the phototransduction cascade. Nature. 1994 Jul 7;370(6484):59–61. [PubMed]
  • Bloomquist BT, Shortridge RD, Schneuwly S, Perdew M, Montell C, Steller H, Rubin G, Pak WL. Isolation of a putative phospholipase C gene of Drosophila, norpA, and its role in phototransduction. Cell. 1988 Aug 26;54(5):723–733. [PubMed]
  • Lee YJ, Dobbs MB, Verardi ML, Hyde DR. dgq: a drosophila gene encoding a visual system-specific G alpha molecule. Neuron. 1990 Dec;5(6):889–898. [PubMed]
  • Talluri S, Bhatt A, Smith DP. Identification of a Drosophila G protein alpha subunit (dGq alpha-3) expressed in chemosensory cells and central neurons. Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11475–11479. [PMC free article] [PubMed]
  • Pollock JA, Benzer S. Transcript localization of four opsin genes in the three visual organs of Drosophila; RH2 is ocellus specific. Nature. 1988 Jun 23;333(6175):779–782. [PubMed]
  • Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403–410. [PubMed]
  • Higgins DG, Bleasby AJ, Fuchs R. CLUSTAL V: improved software for multiple sequence alignment. Comput Appl Biosci. 1992 Apr;8(2):189–191. [PubMed]
  • Schneider TD, Stephens RM. Sequence logos: a new way to display consensus sequences. Nucleic Acids Res. 1990 Oct 25;18(20):6097–6100. [PMC free article] [PubMed]
  • Fujita SC, Inoue H, Yoshioka T, Hotta Y. Quantitative tissue isolation from Drosophila freeze-dried in acetone. Biochem J. 1987 Apr 1;243(1):97–104. [PMC free article] [PubMed]
  • Tso JY, Sun XH, Wu R. Structure of two unlinked Drosophila melanogaster glyceraldehyde-3-phosphate dehydrogenase genes. J Biol Chem. 1985 Jul 5;260(13):8220–8228. [PubMed]
  • Robison K, Gilbert W, Church GM. Large scale bacterial gene discovery by similarity search. Nat Genet. 1994 Jun;7(2):205–214. [PubMed]
  • Noel JP, Hamm HE, Sigler PB. The 2.2 A crystal structure of transducin-alpha complexed with GTP gamma S. Nature. 1993 Dec 16;366(6456):654–663. [PubMed]
  • Lambright DG, Noel JP, Hamm HE, Sigler PB. Structural determinants for activation of the alpha-subunit of a heterotrimeric G protein. Nature. 1994 Jun 23;369(6482):621–628. [PubMed]
  • Lambright DG, Sondek J, Bohm A, Skiba NP, Hamm HE, Sigler PB. The 2.0 A crystal structure of a heterotrimeric G protein. Nature. 1996 Jan 25;379(6563):311–319. [PubMed]
  • Pennington SR. GTP-binding proteins 1: heterotrimeric G proteins. Protein Profile. 1995;2(3):167–315. [PubMed]
  • Carlson JR. Olfaction in Drosophila: from odor to behavior. Trends Genet. 1996 May;12(5):175–180. [PubMed]
  • Riesgo-Escovar J, Raha D, Carlson JR. Requirement for a phospholipase C in odor response: overlap between olfaction and vision in Drosophila. Proc Natl Acad Sci U S A. 1995 Mar 28;92(7):2864–2868. [PMC free article] [PubMed]
  • Stocker RF. The organization of the chemosensory system in Drosophila melanogaster: a review. Cell Tissue Res. 1994 Jan;275(1):3–26. [PubMed]
  • Lee YJ, Shah S, Suzuki E, Zars T, O'Day PM, Hyde DR. The Drosophila dgq gene encodes a G alpha protein that mediates phototransduction. Neuron. 1994 Nov;13(5):1143–1157. [PubMed]
  • Smith DP, Shieh BH, Zuker CS. Isolation and structure of an arrestin gene from Drosophila. Proc Natl Acad Sci U S A. 1990 Feb;87(3):1003–1007. [PMC free article] [PubMed]
  • Hyde DR, Mecklenburg KL, Pollock JA, Vihtelic TS, Benzer S. Twenty Drosophila visual system cDNA clones: one is a homolog of human arrestin. Proc Natl Acad Sci U S A. 1990 Feb;87(3):1008–1012. [PMC free article] [PubMed]
  • Dolph PJ, Ranganathan R, Colley NJ, Hardy RW, Socolich M, Zuker CS. Arrestin function in inactivation of G protein-coupled receptor rhodopsin in vivo. Science. 1993 Jun 25;260(5116):1910–1916. [PubMed]
  • Pollock JA, Benzer S. Transcript localization of four opsin genes in the three visual organs of Drosophila; RH2 is ocellus specific. Nature. 1988 Jun 23;333(6175):779–782. [PubMed]
  • Mismer D, Michael WM, Laverty TR, Rubin GM. Analysis of the promoter of the Rh2 opsin gene in Drosophila melanogaster. Genetics. 1988 Sep;120(1):173–180. [PMC free article] [PubMed]
  • Kim S, McKay RR, Miller K, Shortridge RD. Multiple subtypes of phospholipase C are encoded by the norpA gene of Drosophila melanogaster. J Biol Chem. 1995 Jun 16;270(24):14376–14382. [PubMed]
  • Giebultowicz JM, Riemann JG, Raina AK, Ridgway RL. Circadian system controlling release of sperm in the insect testes. Science. 1989 Sep 8;245(4922):1098–1100. [PubMed]
  • Hall JC. Tripping along the trail to the molecular mechanisms of biological clocks. Trends Neurosci. 1995 May;18(5):230–240. [PubMed]
  • Hardin PE. Analysis of period mRNA cycling in Drosophila head and body tissues indicates that body oscillators behave differently from head oscillators. Mol Cell Biol. 1994 Nov;14(11):7211–7218. [PMC free article] [PubMed]
  • Ryba NJ, Findlay JB, Reid JD. The molecular cloning of the squid (Loligo forbesi) visual Gq-alpha subunit and its expression in Saccharomyces cerevisiae. Biochem J. 1993 Jun 1;292(Pt 2):333–341. [PMC free article] [PubMed]
  • Hardie RC. A histamine-activated chloride channel involved in neurotransmission at a photoreceptor synapse. Nature. 1989 Jun 29;339(6227):704–706. [PubMed]
  • Liu C, Gillette MU. Cholinergic regulation of the suprachiasmatic nucleus circadian rhythm via a muscarinic mechanism at night. J Neurosci. 1996 Jan 15;16(2):744–751. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...