The alpha1-adrenergic receptor plays a critical role in sympathetic neuro-transmission mediating responses involved, for example, in circulatory homeostasis, metabolism and central nervous system function, such as vasoconstriction, hepatic glycogenolysis and alterations in locomotor activity. Recent evidence suggests that alpha1-adrenergic receptor signalling occurs via a unique mechanism involving membrane polyphosphoinositide breakdown. Activation of this receptor-linked pathway leads to cellular calcium mobilization and may involve coupling via an as yet uncharacterized guanine nucleotide-binding regulatory protein. We have previously purified the mammalian alpha1-adrenergic receptor to homogeneity and investigated its biophysical and structural properties, both directly and after covalent labeling of the receptor with a specific high-affinity, radioiodinated photoaffinity probe that we developed. The major focus of this application is the isolation of a cDNA clone for the receptor using molecular biology strategies as well as more traditional approaches based on amino acid sequence data determined from internal peptides liberated from the purified receptor protein. The receptor cDNA will then be used to clone the receptor's gene and to perform more detailed investigations of receptor expression and receptor structure-function relationships. These studies will involve the use of molecular biology techniques, reconstitution studies and anti-receptor antibodies. Anti-receptor antibodies will be developed using peptide antigens based on various amino acid sequences determined from the elucidated primary structure of the receptor. Additionally, we propose to test the hypothesis that a guanine nucleotide-binding regulatory protein couples the alpha1-adrenergic receptor to polyphosphoinositide breakdown. Initially, studies will be performed to rigorously define the involvement of such a regulatory protein in alpha:- receptor functioning, and to gain mechanistic insights in receptor- regulatory protein interactions. With the availability of this data, we propose to purify this regulatory protein and to evaluate its molecular characteristics using affinity labeling and reconstitution techniques. When completed, these studies should provide important insights into the biochemical and molecular mechanisms of signal transduction by the alpha1-adrenergic receptor. Using the tools of protein and immunochemistry, as well as molecular biology, new approaches will have been developed for understanding alpha1-adrenergic receptor expression, and for defining the kinetics and stoichiometry of its interaction with cellular effector proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
7R01NS019583-08
Application #
3399692
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1989-07-01
Project End
1991-06-30
Budget Start
1989-07-01
Budget End
1990-06-30
Support Year
8
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Cleveland Clinic Lerner
Department
Type
DUNS #
017730458
City
Cleveland
State
OH
Country
United States
Zip Code
44195
Guarino, R D; Perez, D M; Piascik, M T (1996) Recent advances in the molecular pharmacology of the alpha 1-adrenergic receptors. Cell Signal 8:323-33
Graham, R M; Perez, D M; Hwa, J et al. (1996) alpha 1-adrenergic receptor subtypes. Molecular structure, function, and signaling. Circ Res 78:737-49
Perez, D M; Hwa, J; Gaivin, R et al. (1996) Constitutive activation of a single effector pathway: evidence for multiple activation states of a G protein-coupled receptor. Mol Pharmacol 49:112-22
deS Senanayake, P; Denker, J; Bravo, E L et al. (1995) Production, characterization, and expression of neuropeptide Y by human pheochromocytoma. J Clin Invest 96:2503-9
Piascik, M T; Guarino, R D; Smith, M S et al. (1995) The specific contribution of the novel alpha-1D adrenoceptor to the contraction of vascular smooth muscle. J Pharmacol Exp Ther 275:1583-9
Riek, R P; Handschumacher, M D; Sung, S S et al. (1995) Evolutionary conservation of both the hydrophilic and hydrophobic nature of transmembrane residues. J Theor Biol 172:245-58
Piascik, M T; Smith, M S; Soltis, E E et al. (1994) Identification of the mRNA for the novel alpha 1D-adrenoceptor and two other alpha 1-adrenoceptors in vascular smooth muscle. Mol Pharmacol 46:30-40
De Young, M B; Keller, J C; Graham, R M et al. (1994) Brefeldin A defines distinct pathways for atrial natriuretic factor secretion in neonatal rat atrial and ventricular myocytes. Circ Res 74:33-40
Perez, D M; Piascik, M T; Malik, N et al. (1994) Cloning, expression, and tissue distribution of the rat homolog of the bovine alpha 1C-adrenergic receptor provide evidence for its classification as the alpha 1A subtype. Mol Pharmacol 46:823-31
Noda, K; Saad, Y; Graham, R M et al. (1994) The high affinity state of the beta 2-adrenergic receptor requires unique interaction between conserved and non-conserved extracellular loop cysteines. J Biol Chem 269:6743-52

Showing the most recent 10 out of 36 publications