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Love CR, Gautam S, Lama C, Le NH, Dauwalder B. The Drosophila dopamine 2-like receptor D2R (Dop2R) is required in the blood brain barrier for male courtship. GENES, BRAIN, AND BEHAVIOR 2023; 22:e12836. [PMID: 36636829 PMCID: PMC9994173 DOI: 10.1111/gbb.12836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/11/2022] [Accepted: 12/22/2022] [Indexed: 01/14/2023]
Abstract
The blood brain barrier (BBB) has the essential function to protect the brain from potentially hazardous molecules while also enabling controlled selective uptake. How these processes and signaling inside BBB cells control neuronal function is an intense area of interest. Signaling in the adult Drosophila BBB is required for normal male courtship behavior and relies on male-specific molecules in the BBB. Here we show that the dopamine receptor D2R is expressed in the BBB and is required in mature males for normal mating behavior. Conditional adult male knockdown of D2R in BBB cells causes courtship defects. The courtship defects observed in genetic D2R mutants can be rescued by expression of normal D2R specifically in the BBB of adult males. Drosophila BBB cells are glial cells. Our findings thus identify a specific glial function for the DR2 receptor and dopamine signaling in the regulation of a complex behavior.
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Affiliation(s)
- Cameron R Love
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA.,Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey, USA
| | - Sumit Gautam
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Chamala Lama
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Nhu Hoa Le
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Brigitte Dauwalder
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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2
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Agrawal T, Hasan G. Maturation of a central brain flight circuit in Drosophila requires Fz2/Ca²⁺ signaling. eLife 2015; 4. [PMID: 25955970 PMCID: PMC4451221 DOI: 10.7554/elife.07046] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/07/2015] [Indexed: 12/02/2022] Open
Abstract
The final identity of a differentiated neuron is determined by multiple signaling events, including activity dependent calcium transients. Non-canonical Frizzled2 (Fz2) signaling generates calcium transients that determine neuronal polarity, neuronal migration, and synapse assembly in the developing vertebrate brain. Here, we demonstrate a requirement for Fz2/Ca2+ signaling in determining the final differentiated state of a set of central brain dopaminergic neurons in Drosophila, referred to as the protocerebral anterior medial (PAM) cluster. Knockdown or inhibition of Fz2/Ca2+ signaling during maturation of the flight circuit in pupae reduces Tyrosine Hydroxylase (TH) expression in the PAM neurons and affects maintenance of flight. Thus, we demonstrate that Fz2/Ca2+ transients during development serve as a pre-requisite for normal adult behavior. Our results support a neural mechanism where PAM neuron send projections to the α' and β' lobes of a higher brain centre, the mushroom body, and function in dopaminergic re-inforcement of flight. DOI:http://dx.doi.org/10.7554/eLife.07046.001 The fruit fly Drosophila melanogaster is an aerial acrobat. These insects can suddenly change direction in less than one hundredth of a second, explaining why a moving fly can be so difficult to swat. To perform their aerial manoeuvres, the flies continually combine information from multiple senses, including vision, hearing and smell, and use these data to control the activity of the neural circuits that support flight. These flight circuits are established during the pupal stage of fly development, during which the fly transforms from a larva into its adult form. In 2013, researchers showed that a protein called dFrizzled2 must be present in pupae for flight circuits to mature correctly. This protein forms part of a pathway that ultimately controls which specific chemicals—called neurotransmitters—are released by neurons to communicate with other cells. Agrawal and Hasan—who worked on the 2013 study—now extend their findings to investigate the role of dFrizzled2 in more detail. The new experiments show that for the flight circuits to mature, dFrizzled2 must be active in a cluster of neurons known collectively as PAM. Specifically, dFrizzled2 is needed to make an enzyme that helps to produce a neurotransmitter called dopamine. This in turn enables the PAM neurons to communicate with a region of the fruit fly brain called the mushroom body, which it thought to play an important role in complex behaviors such as reward-based learning. The absence of dFrizzled2 results in adult flies that rarely remain airborne for more than 20 s at a time, whereas normal flies can typically fly for over 700 s. Given that dopamine is known to signal reward, one possibility is that the dopamine signals from the PAM neurons to the mushroom body serve as a reward to encourage continuous flight. Mutant flies that lack dFrizzled2—and thus these dopamine signals—lose their motivation to fly after only a few seconds. Overall, Agrawal and Hasan's findings suggest that the mushroom body has an important role in coordinating a fly's movements with information from it senses. Future research will be needed to determine exactly how the mushroom body performs this role. DOI:http://dx.doi.org/10.7554/eLife.07046.002
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Affiliation(s)
- Tarjani Agrawal
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
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3
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Hoxha V, Lama C, Chang PL, Saurabh S, Patel N, Olate N, Dauwalder B. Sex-specific signaling in the blood-brain barrier is required for male courtship in Drosophila. PLoS Genet 2013; 9:e1003217. [PMID: 23359644 PMCID: PMC3554526 DOI: 10.1371/journal.pgen.1003217] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 11/20/2012] [Indexed: 01/12/2023] Open
Abstract
Soluble circulating proteins play an important role in the regulation of mating behavior in Drosophila melanogaster. However, how these factors signal through the blood–brain barrier (bbb) to interact with the sex-specific brain circuits that control courtship is unknown. Here we show that male identity of the blood–brain barrier is necessary and that male-specific factors in the bbb are physiologically required for normal male courtship behavior. Feminization of the bbb of adult males significantly reduces male courtship. We show that the bbb–specific G-protein coupled receptor moody and bbb–specific Go signaling in adult males are necessary for normal courtship. These data identify sex-specific factors and signaling processes in the bbb as important regulators of male mating behavior. Complex behaviors such as mating behavior are controlled by the brain. Ensembles of brain cells work in networks to ensure proper behavior at the right time. While the state of these cells plays an important role in whether and how the behavior is displayed, information from outside the brain is also required. Often, this information is provided by hormones that are present in the circulating fluid (such as the blood). However, the brain is protected by a layer of very tight cells, the so-called blood–brain barrier, that keeps unwanted molecules out. So how then do hormones and other regulatory factors “talk” to the brain? We are studying this question by examining the mating behavior of males of a model organism, the fruit fly Drosophila melanogaster. We have found that the blood–brain barrier cells themselves contain male-specific molecules that play an important role. When they are absent, courtship behavior is compromised. We have also identified how outside factors talk to the brain: by using a cellular signaling protein and a particular signaling pathway. Together they are well suited to pass on outside information to the brain network that regulates mating behavior.
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Affiliation(s)
- Valbona Hoxha
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Chamala Lama
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Peter L. Chang
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Sumit Saurabh
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Naiya Patel
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Nicole Olate
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Brigitte Dauwalder
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
- * E-mail:
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4
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Chatterjee A, Roman G, Hardin PE. Go contributes to olfactory reception in Drosophila melanogaster. BMC PHYSIOLOGY 2009; 9:22. [PMID: 19943954 PMCID: PMC2789035 DOI: 10.1186/1472-6793-9-22] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 11/28/2009] [Indexed: 11/11/2022]
Abstract
Background Seven-transmembrane receptors typically mediate olfactory signal transduction by coupling to G-proteins. Although insect odorant receptors have seven transmembrane domains like G-protein coupled receptors, they have an inverted membrane topology and function as ligand-gated cation channels. Consequently, the involvement of cyclic nucleotides and G proteins in insect odor reception is controversial. Since the heterotrimeric Goα subunit is expressed in Drosophila olfactory receptor neurons, we reasoned that Go acts together with insect odorant receptor cation channels to mediate odor-induced physiological responses. Results To test whether Go dependent signaling is involved in mediating olfactory responses in Drosophila, we analyzed electroantennogram and single-sensillum recording from flies that conditionally express pertussis toxin, a specific inhibitor of Go in Drosophila. Pertussis toxin expression in olfactory receptor neurons reversibly reduced the amplitude and hastened the termination of electroantennogram responses induced by ethyl acetate. The frequency of odor-induced spike firing from individual sensory neurons was also reduced by pertussis toxin. These results demonstrate that Go signaling is involved in increasing sensitivity of olfactory physiology in Drosophila. The effect of pertussis toxin was independent of odorant identity and intensity, indicating a generalized involvement of Go in olfactory reception. Conclusion These results demonstrate that Go is required for maximal physiological responses to multiple odorants in Drosophila, and suggest that OR channel function and G-protein signaling are required for optimal physiological responses to odors.
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Affiliation(s)
- Abhishek Chatterjee
- Department of Biology and Center for Biological Clock Research, Texas A&M University, College Station, TX 77843, USA.
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5
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Ferris J, Ge H, Liu L, Roman G. G(o) signaling is required for Drosophila associative learning. Nat Neurosci 2006; 9:1036-40. [PMID: 16845387 DOI: 10.1038/nn1738] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Accepted: 06/14/2006] [Indexed: 11/09/2022]
Abstract
Heterotrimeric G(o) is one of the most abundant proteins in the brain, yet relatively little is known of its neural functions in vivo. Here we demonstrate that G(o) signaling is required for the formation of associative memory. In Drosophila melanogaster, pertussis toxin (PTX) is a selective inhibitor of G(o) signaling. The postdevelopmental expression of PTX within mushroom body neurons robustly and reversibly inhibits associative learning. The effect of G(o) inhibition is distributed in both gamma- and alpha/beta-lobe mushroom body neurons. However, the expression of PTX in neurons adjacent to the mushroom bodies does not affect memory. PTX expression also does not interact genetically with a rutabaga adenylyl cyclase loss-of-function mutation. Thus, G(o) defines a new signaling pathway required in mushroom body neurons for the formation of associative memory.
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Affiliation(s)
- Jacob Ferris
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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6
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Dyer M, Day K. Expression of Plasmodium falciparum trimeric G proteins and their involvement in switching to sexual development. Mol Biochem Parasitol 2000; 110:437-48. [PMID: 11071298 DOI: 10.1016/s0166-6851(00)00288-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Both cholera and pertussis toxins were used to label and study the expression of heterotrimeric G protein alpha subunits in Plasmodium falciparum extracts. Expression of these proteins is developmentally regulated throughout the erythrocytic cycle with peak expression during early asexual development and in mature sexual stages. Treatment of P. falciparum cultures with cholera toxin causes an increase in conversion to sexual development, and at the same concentration has a marginal inhibitory effect on asexual growth and division. Through precise synchronisation of the parasites' asexual cell cycle, we have defined the period of sensitivity to this induction at around the time of invasion, one cycle before the development of the sexual form. Fluorescent microscopy confirmed that access of the toxin to the parasite is limited to the invasive form--the free merozoite, while further labelling studies revealed expression of a single G protein alpha subunit in these stages. These observations are consistent with the view that a G protein-dependent signal transduction pathway is involved in coupling the parasite's environment to commitment to sexual development (gametocytogenesis). This means of artificially stimulating the pathways leading to sexual development can now be used to biochemically follow the activation of the signalling pathways involved.
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Affiliation(s)
- M Dyer
- Wellcome Trust Centre for the Epidemiology of Infectious Disease, Department of Zoology, University Oxford, UK.
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7
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Dyer M, Day K. Expression of Plasmodium falciparum trimeric G proteins and their involvement in switching to sexual development. Mol Biochem Parasitol 2000; 108:67-78. [PMID: 10802319 DOI: 10.1016/s0166-6851(00)00205-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Both cholera and pertussis toxins were used to label and study the expression of heterotrimeric G protein alpha subunits in Plasmodium falciparum extracts. Expression of these proteins is developmentally regulated throughout the erythrocytic cycle with peak expression during early asexual development and in mature sexual stages. Treatment of P. falciparum cultures with cholera toxin causes an increase in conversion to sexual development, and at the same concentration has a marginal inhibitory effect on asexual growth and division. Through precise synchronisation of the parasites' asexual cell cycle, we have defined the period of sensitivity to this induction at around the time of invasion, one cycle before the development of the sexual form. Fluorescent microscopy confirmed that access of the toxin to the parasite is limited to the invasive form - the free merozoite, while further labelling studies revealed expression of a single G protein alpha subunit in these stages. These observations are consistent with the view that a G protein-dependent signal transduction pathway is involved in coupling the parasite's environment to commitment to sexual development (gametocytogenesis). This means of artificially stimulating the pathways leading to sexual development can now be used to biochemically follow the activation of the signalling pathways involved.
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Affiliation(s)
- M Dyer
- Wellcome Trust Centre for the Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
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8
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Wang Y, Telfer WH. Pertussis toxin-sensitive G protein that supports vitellogenin uptake by promoting patency. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 1998; 39:36-45. [PMID: 9816673 DOI: 10.1002/(sici)1520-6327(1998)39:1<36::aid-arch5>3.0.co;2-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ovarian follicles of Hyalophora cecropia stopped accumulating [35S]vitellogenin when incubated in pertussis toxin, a Gi protein inactivator. At a cellular level, the responses to pertusis toxin resembled those described earlier to cell-permeant analogs of cyclic AMP. They included accelerated 36Cl-exchange, 86Rb+ uptake, and follicle cell swelling, which in turn resulted in a loss of epithelial patency. A 34% rise in follicular cAMP content accompanied these changes. In particulate fractions of follicle homogenates, pertussis toxin catalyzed the ADP-ribosylation of a polypeptide that resolved at 39 kDa in SDS-PAGE; rabbit antibodies to a C-terminal decapeptide common to 39 kDa mammalian Gi alpha-3 and G(o) alpha were bound in immunoblots at this same location. The findings suggest that a pertussis toxin-sensitive G alpha facilitates epithelial patency during vitellogenesis by suppressing cAMP levels. When follicles are released from this restraint, either experimentally with pertussis toxin or by progressing to the next phase in their normal program of development, cAMP levels rise and vitellogenesis terminates.
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Affiliation(s)
- Y Wang
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6084, USA
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9
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Torres-Márquez ME, Macías-Silva M, Vega-Segura A. Identification of a functional Gs protein in Euglena gracilis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1996; 115:233-7. [PMID: 9375361 DOI: 10.1016/s0742-8413(96)00105-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We found a Gs protein coupled to adenylyl cyclase in a free-living protist, Euglena gracilis. This Gs protein of approximately 42 kDa is substrate for cholera toxin and is recognized by an antibody against the C-terminal decapeptide of Gs. Furthermore, this protein is coupled to adenylyl cyclase, as shown by: (a) the activation of the enzyme by GTP-analogues and (b) the effect of cholera toxin on cAMP accumulation in intact cells and the continuous activation of adenylyl cyclase activity in membranes. These data indicate that the Gs-adenylyl cyclase-coupled system is already apparent in the protist kingdom.
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Affiliation(s)
- M E Torres-Márquez
- Departamento de Bioquímica, Instituto Nacional de Cardiologia Ignacio Chávez, México, D.F., México
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10
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Copenhaver PF, Horgan AM, Nichols DC, Rasmussen MA. Developmental expression of heterotrimeric G proteins in the nervous system of Manduca sexta. JOURNAL OF NEUROBIOLOGY 1995; 26:461-84. [PMID: 7602312 DOI: 10.1002/neu.480260402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The heterotrimeric G proteins are a conserved family of guanyl nucleotide-binding proteins that appear in all eukaryotic cells but whose developmental functions are largely unknown. We have examined the developmental expression of representative G proteins in the developing nervous system of the moth Manduca sexta. Using affinity-purified antisera against different G alpha subunits, we found that each of the G proteins exhibited distinctive patterns of expression within the developing central nervous system (CNS), and that these patterns underwent progressive phases of spatial and temporal regulation that corresponded to specific aspects of neuronal differentiation. Several of the G proteins examined (including Gs alpha and G(o) alpha) were expressed in an apparently ubiquitous manner in all neurons, but other proteins (including Gi alpha) were ultimately confined to a more restricted subset of cells in the mature CNS. Although most of the G proteins examined could be detected within the central ganglia, only G(o) alpha-related proteins were seen in the developing peripheral nerves; manipulations of G protein activity in cultured embryos suggested that this class of G protein may contribute to the regulation of neuronal motility during axonal outgrowth. G(o) alpha-related proteins were also localized to the developing axons and terminals of the developing adult limb during metamorphosis. These intracellular signaling molecules may, therefore, play similar developmental roles in both the embryonic and postembryonic nervous system.
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Affiliation(s)
- P F Copenhaver
- Department of Cell Biology and Anatomy, Oregon Health Sciences University, Portland 97201, USA
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11
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Fitch CL, de Sousa SM, O'Day PM, Neubert TA, Plantilla CM, Spencer M, Yarfitz S, Apte D, Hurley JB. Pertussis toxin expression in Drosophila alters the visual response and blocks eating behaviour. Cell Signal 1993; 5:187-207. [PMID: 8499226 DOI: 10.1016/0898-6568(93)90070-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Pertussis toxin inactivates certain G-proteins by introducing an ADP-ribose group near the carboxyl-terminus of the alpha-subunit. The major pertussis toxin substrate in Drosophila tissues is Go alpha. We introduced a pertussis toxin gene under control of the hsp70 heat-shock promoter into the Drosophila genome. When heat-shocked, transformed flies produce active pertussis toxin which ADP-ribosylates endogenous Go alpha. Pertussis toxin is expressed in photoreceptors, in the lamina of the eye and in epithelial cells lining the gut. As expected from the absence of Go alpha in photoreceptors, pertussis toxin does not affect the photoreceptor component of the Drosophila visual response. However, it abolishes light on- and off-transients in the electroretinogram. These transients normally arise from the lamina, a tissue where Go alpha transcripts have been detected. Pertussis toxin expression also blocks embryonic development and shortens the lifetime of adult Drosophila. Following heat-shock, transformed adults are active, but they fail to take up nutrients because they stop eating. High energy metabolites are significantly depleted shortly after pertussis toxin expression is induced and the flies die within 48 h.
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Affiliation(s)
- C L Fitch
- Howard Hughes Medical Institute, University of Washington, Seattle 98195
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12
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Taggart P, Landau M. Characterization of a G-protein from the mandibular organ of the lobster Homarus americanus (Nephropidae, Decapoda). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1992; 102:799-802. [PMID: 1395512 DOI: 10.1016/0305-0491(92)90083-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. GTP-binding activity was found in both calf brain and male lobster mandibular organ (MO). There was approximately two to three times as much binding in the calf brain. 2. The GTP-binding activity could be extracted from the calf brain with sodium cholate, but not from the MOs. 3. Using ADP-ribosylation catalyzed by pertussis toxin, GTP-binding was shown to be the result of the presence of G-protein. In the lobster MO the G-protein alpha subunit has a molecular weight of about 42 kDa and may be of the Go or Gi varieties.
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Affiliation(s)
- P Taggart
- Department of Chemistry, Stockton State College, Pomona, NJ 08240
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13
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Söling A, Walther C, Rosenthal W. Identification of proteins resembling G-protein alpha subunits in locust muscle. Biochem Biophys Res Commun 1991; 180:1075-82. [PMID: 1953712 DOI: 10.1016/s0006-291x(05)81176-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In locust skeletal muscle, FMRFamide-like peptides decrease a K+ conductance. Functional data suggest the involvement of G-proteins. For identification of G-protein alpha-subunits, membranes of locust skeletal muscle were probed with ADP-ribosylating bacterial toxins, the photoreactive GTP analog, [alpha-32P]GTP azidoanilide, and with antibodies against mammalian alpha-subunits. Multiple guanine nucleotide-binding proteins of approximately 24-95 kDa were detected. Pertussis toxin catalyzed the ADP-ribosylation of two proteins comigrating with the ADP-ribosylated alpha-subunits of the mammalian G-proteins Go and Gi. Cholera toxin promoted ADP-ribosylation of a protein comigrating with mammalian cholera toxin substrates (i.e., Gs alpha-subunits). An antibody against mammalian Go alpha-subunits detected a 54-kDa protein. Thus proteins with properties of mammalian G-protein subunits are present in insect muscle.
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Affiliation(s)
- A Söling
- Institut für Pharmakologie, Freie Universität Berlin, F.R.G
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14
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Meller VH, Gilbert LI. Occurrence, quaternary structure and function of G protein subunits in an insect endocrine gland. Mol Cell Endocrinol 1990; 74:133-41. [PMID: 2128628 DOI: 10.1016/0303-7207(90)90115-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The occurrence, structure and function of the alpha and beta subunits of GTP-binding proteins (G proteins) were investigated in the Manduca sexta prothoracic gland, a tissue which possesses a hormonally regulated adenylate cyclase. Subunit-specific antibodies were utilized in immunoblotting studies of tissue from Manduca prothoracic glands, brain, eyes and antennae, and compared to the substrates present in the heads of Drosophila, as well as in a mammalian cell line. All Manduca tissues examined showed putative G beta subunits of 37 and 38 kDa, an unidentified alpha subunit of 41 kDa, in addition to an eye specific alpha subunit of 42 kDa. Manduca tissues also produced putative Gs alpha subunits of 48 and 51 kDa which were coupled to prothoracic gland adenylate cyclase as demonstrated by immunoprecipitation. Prothoracic gland G proteins have a definite and limited quaternary structure, consistent with a heterotrimeric model, as demonstrated by crosslinking of prothoracic gland membrane preparations followed by immunoblotting. These studies also yielded data on relative titers of alpha subunits, and suggest that Gs alpha is present in lower amounts than other alpha subunits. The G protein subunits studied in the prothoracic gland appear strikingly similar in molecular weight, function and structure to their mammalian counterparts.
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Affiliation(s)
- V H Meller
- Department of Biology, University of North Carolina, Chapel Hill 27599
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15
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Lee YJ, Dobbs MB, Verardi ML, Hyde DR. dgq: a drosophila gene encoding a visual system-specific G alpha molecule. Neuron 1990; 5:889-98. [PMID: 2125225 DOI: 10.1016/0896-6273(90)90349-k] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We describe the isolation and preliminary characterization of a new G alpha gene (dgq) in Drosophila. The dgq gene is differentially spliced, yielding two putative proteins, both of which contain guanine nucleotide binding and hydrolysis domains and share 50% identity with transducins and other G proteins. These proteins represent a new class of G alpha subunits because they lack both high amino acid identity with other G alpha proteins and the pertussis toxin ADP ribosylation site. The dgq mRNA is detected by RNA-RNA Northern hybridization in wild-type heads but not in wild-type bodies or in the mutant eyes absent heads. Tissue in situ hybridization detects dgq expression only in the retina and ocellus of the adult head, making it a prime candidate for encoding the Drosophila transducin analog, the G protein required for phototransduction.
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Affiliation(s)
- Y J Lee
- Department of Biological Sciences, University of Notre Dame, Indiana 46556
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16
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Tsuda M, Tsuda T. Two distinct light regulated G-proteins in octopus photoreceptors. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1052:204-10. [PMID: 2108729 DOI: 10.1016/0167-4889(90)90077-q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two distinct light-regulated G-proteins were found in octopus photoreceptors. Gip, a 41 kDa protein from washed microvilli, was ADP ribosylated by pertussis toxin in the presence of GDP in the dark. Light and GTP analogues were inhibitory as with transducin (Gt; G-protein in vertebrate photoreceptors). G34, a 34 kDa protein from fresh octopus retina, was ADP ribosylated by both cholera and pertussis toxin in the dark. Light inhibited labeling of the 34 kDa protein by both toxins. Unlike Gip, G34 is soluble and is very labile to heat, freezing and thawing. Prolonged incubation of octopus retina with cholera toxin and labeled NAD produced an additional radioactive band at 46 kDa. Labeling of the 46 kDa protein, Gsp, was greatly enhanced by GTP analogues, but inhibited by a GDP analogue as with Gs in hormone-sensitive adenylate cyclase. In contrast to Gip and G34, labeling of the 46 kDa protein (Gsp) was not influenced by light. The two distinct light-regulated G-proteins, Gip and G34, found in octopus photoreceptors might be involved in either phototransduction or photoadaptation. The function of Gsp is not known.
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Affiliation(s)
- M Tsuda
- Department of Physics, Sapporo Medical College, Japan
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Two forms of Drosophila melanogaster Gs alpha are produced by alternate splicing involving an unusual splice site. Mol Cell Biol 1990. [PMID: 2106072 DOI: 10.1128/mcb.10.3.910] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
G proteins are responsible for modulating the activity of intracellular effector systems in response to receptor activation. The stimulatory G protein Gs is responsible for activation of adenylate cyclase in response to a variety of hormonal signals. In this report, we describe the structure of the gene for the alpha subunit of Drosophila melanogaster Gs. The gene is approximately 4.5 kilobases long and is divided into nine exons. The exon-intron structure of the Drosophila gene shows substantial similarity to that of the human gene for Gs alpha. Alternate splicing of intron 7, involving either use of an unusual TG or consensus AG 3' splice site, results in transcripts which code for either a long (DGs alpha L) or short (DGs alpha S) form of Gs alpha. These subunits differ by inclusion or deletion of three amino acids and substitution of a Ser for a Gly. The two forms of Drosophila Gs alpha differ in a region where no variation in the primary sequence of vertebrate Gs alpha subunits has been observed. In vitro translation experiments demonstrated that the Drosophila subunits migrate anomalously on sodium dodecyl sulfate-polyacrylamide gels with apparent molecular weights of 51,000 and 48,000. Additional Gs alpha transcript heterogeneity reflects the use of multiple polyadenylation sites.
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Quan F, Forte MA. Two forms of Drosophila melanogaster Gs alpha are produced by alternate splicing involving an unusual splice site. Mol Cell Biol 1990; 10:910-7. [PMID: 2106072 PMCID: PMC360930 DOI: 10.1128/mcb.10.3.910-917.1990] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
G proteins are responsible for modulating the activity of intracellular effector systems in response to receptor activation. The stimulatory G protein Gs is responsible for activation of adenylate cyclase in response to a variety of hormonal signals. In this report, we describe the structure of the gene for the alpha subunit of Drosophila melanogaster Gs. The gene is approximately 4.5 kilobases long and is divided into nine exons. The exon-intron structure of the Drosophila gene shows substantial similarity to that of the human gene for Gs alpha. Alternate splicing of intron 7, involving either use of an unusual TG or consensus AG 3' splice site, results in transcripts which code for either a long (DGs alpha L) or short (DGs alpha S) form of Gs alpha. These subunits differ by inclusion or deletion of three amino acids and substitution of a Ser for a Gly. The two forms of Drosophila Gs alpha differ in a region where no variation in the primary sequence of vertebrate Gs alpha subunits has been observed. In vitro translation experiments demonstrated that the Drosophila subunits migrate anomalously on sodium dodecyl sulfate-polyacrylamide gels with apparent molecular weights of 51,000 and 48,000. Additional Gs alpha transcript heterogeneity reflects the use of multiple polyadenylation sites.
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Affiliation(s)
- F Quan
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201-3098
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Raming K, Krieger J, Breer H. Molecular cloning, sequencing and expression of cDNA encoding a G0-protein from insect. Cell Signal 1990; 2:311-21. [PMID: 2119206 DOI: 10.1016/0898-6568(90)90059-j] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A locust cDNA clone encoding the complete sequence of a guanine nucleotide-binding protein was isolated and its nucleotide sequence determined. Comparing the deduced amino acid sequence with primary structures of other G-proteins revealed striking homologies with the vertebrate G0-protein. The cloned cDNA was expressed and the translation product detected by specific antibodies. Northern blot analysis revealed that the corresponding mRNA exists in two forms, preferentially expressed in the nervous tissue.
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Affiliation(s)
- K Raming
- University Stuttgart-Hohenheim, Institute of Zoophysiology, F.R.G
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Raming K, Breer H. Comparative studies on G-proteins in the nervous tissue of invertebrates. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0305-0491(90)90329-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Schmidt CJ, Garen-Fazio S, Chow YK, Neer EJ. Neuronal expression of a newly identified Drosophila melanogaster G protein alpha 0 subunit. CELL REGULATION 1989; 1:125-34. [PMID: 2519611 PMCID: PMC361431 DOI: 10.1091/mbc.1.1.125] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Guanine nucleotide-binding proteins (G proteins) mediate signals between activated cell-surface receptors and cellular effectors. A bovine G-protein alpha-subunit cDNA has been used to isolate similar sequences from Drosophila genomic and cDNA libraries. One class, which we call DG alpha 0, hybridized to position 47A on the second chromosome of Drosophila. The nucleotide sequence of the protein coding region of one cDNA has been determined, revealing an alpha subunit that is 81% identical with rat alpha 0. The cDNA hybridizes strongly to a 3.8 kb mRNA and weakly with a 5.3 kb message. Antibodies raised against a trp-E-DG alpha 0 fusion protein recognized a 39,000 Da protein in Drosophila extracts. In situ hybridization to adult Drosophila sections combined with immunohistochemical studies revealed expression throughout the optic lobes and central brain and in the thoracic and abdominal ganglia. DG alpha 0 message and protein were also detected in the antennae, oocytes, and ovarian nurse cells. The neuronal expression of this gene is similar to mammalian alpha 0, which is most abundantly expressed in the brain.
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Affiliation(s)
- C J Schmidt
- Department of Cardiology, Brigham and Women's Hospital, Boston, Massachusetts 02115
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Thambi NC, Quan F, Wolfgang WJ, Spiegel A, Forte M. Immunological and Molecular Characterization of Goα-like Proteins in the Drosophila Central Nervous System. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51503-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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de Sousa SM, Hoveland LL, Yarfitz S, Hurley JB. The Drosophila Go α-like G protein gene produces multiple transcripts and is expressed in the nervous system and in ovaries. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51502-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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24
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Yoon J, Shortridge RD, Bloomquist BT, Schneuwly S, Perdew MH, Pak WL. Molecular characterization of Drosophila Gene Encoding G0 α Subunit Homolog. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51501-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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