The overall aim of this research is to understand the molecular basis of receptor-initiated signal transductions, primarily but not exclusively as they relate to adenylyl cyclase regulation. This includes cyclase stimulaton by Rs-type receptors and inhibition by Ri-type receptors. During the last grant period, we purified and characterized the subunit compositin of Ns and Ni, the coupling proteins that transduce Rs and Ri receptor occupancy into altered adenylyl cyclasle activity. We also described N-mediated regulation of hormone-receptor interactions and reconstituted RN interactions in phospholipid vesicles, using pure Rs and pure Ns and rhodopsin (a Ri analog) and pure Ni. We appear to have cloned the cDNA coding for the Mr = 35,000 beta subunit of N proteins, although final confirmation is still missing. During this coming grant period we wish: 1. To clone the cDNAs for the alpha and gamma subunits of Ns and Ni. 2. To express sn bacteria alpha, beta and gamma subunits of N proteins and study their respective functions as seen after recombination to give N proteins, using as assays the reconstitution in phospholipid vesicles of Rs-Ns and rhodopsin-Ni interactions. 3. To study the genetic organization of genes coding for Ns and Ni subunits and define the mode of biosynthesis of these proteins. 4. To explore if subunit dissociation occurs on receptor-mediated activation of N proteins in the presence of GTP and to determine how Ni acts, as seen after reconstitution in phospholipid vesicles of Ns, Ni, an Rs, an Ri and adenylyl cyclase proper. 5. To develop on the basis of possible sequence homologies between rhodopsin and Ri-type receptors an approach for cloning and determining the primary structure of Ri-type receptors such as alpha2-adrenergic, muscarinic acetylcholine and opioid receptors, or alternatively, to purify the muscarinic acetylcholine receptor and, on the basis of partial primary amino acid sequence determination or polyclonal antibody generation, to clone and determine its primary structure, define homologies with rhodopsin and proceed with cloning of other Ri-type receptors. 6. To explore possible structural homologies between N proteins and ras gene products testing their subunit composition and their possible physical coupling to receptors that do not couple to adenylyl cyclase. This research should significantly advance our understanding of the molecular basis of signal transductions that impinge on cAMP formation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37DK019318-16
Application #
3483286
Study Section
Special Emphasis Panel (NSS)
Project Start
1979-12-01
Project End
1993-11-30
Budget Start
1991-12-01
Budget End
1992-11-30
Support Year
16
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Tang, Guanghua; Wang, Ying; Park, Sangeun et al. (2012) Go2 G protein mediates galanin inhibitory effects on insulin release from pancreatic ? cells. Proc Natl Acad Sci U S A 109:2636-41
Pero, Ralph S; Borchers, Michael T; Spicher, Karsten et al. (2007) Galphai2-mediated signaling events in the endothelium are involved in controlling leukocyte extravasation. Proc Natl Acad Sci U S A 104:4371-6
Fan, Hongkuan; Williams, David L; Zingarelli, Basilia et al. (2007) Differential regulation of lipopolysaccharide and Gram-positive bacteria induced cytokine and chemokine production in macrophages by Galpha(i) proteins. Immunology 122:116-23
Gohla, Antje; Klement, Karinna; Piekorz, Roland P et al. (2007) An obligatory requirement for the heterotrimeric G protein Gi3 in the antiautophagic action of insulin in the liver. Proc Natl Acad Sci U S A 104:3003-8
Fan, Hongkuan; Williams, David L; Zingarelli, Basilia et al. (2006) Differential regulation of lipopolysaccharide and Gram-positive bacteria induced cytokine and chemokine production in splenocytes by Galphai proteins. Biochim Biophys Acta 1763:1051-8
Wei, Bo; Velazquez, Peter; Turovskaya, Olga et al. (2005) Mesenteric B cells centrally inhibit CD4+ T cell colitis through interaction with regulatory T cell subsets. Proc Natl Acad Sci U S A 102:2010-5
Pineda, Victor V; Athos, Jaime I; Wang, Hongbing et al. (2004) Removal of G(ialpha1) constraints on adenylyl cyclase in the hippocampus enhances LTP and impairs memory formation. Neuron 41:153-63
Foerster, Katharina; Groner, Ferdi; Matthes, Jan et al. (2003) Cardioprotection specific for the G protein Gi2 in chronic adrenergic signaling through beta 2-adrenoceptors. Proc Natl Acad Sci U S A 100:14475-80
Dhingra, Anuradha; Jiang, Meisheng; Wang, Tian-Li et al. (2002) Light response of retinal ON bipolar cells requires a specific splice variant of Galpha(o). J Neurosci 22:4878-84
Jiang, M; Spicher, K; Boulay, G et al. (2001) Most central nervous system D2 dopamine receptors are coupled to their effectors by Go. Proc Natl Acad Sci U S A 98:3577-82

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