Obesity is an epidemic with enormous health, economic, and social burdens. Several neuropeptides were found to be involved in regulating energy homeostasis. These neuropeptides act on their cell surface receptors to exert their physiological effects. The melanocortin-3 receptor (MC3R) is increasingly being recognized as an important regulator of energy homeostasis, especially for fat deposit. It is also involved in regulating cardiovascular function and inflammation. The applicant's long-term goals are to understand the structure-function relationships of the human MC3R at the molecular level. The research proposed in this application is aimed at understanding the molecular mechanisms of MC3R coupling to G proteins. The following two specific aims will be pursued: (1) To characterize the intracellular surface of the MC3R that are involved in G protein coupling; (2) To map some of the contact sites between the MC3R and the stimulatory G protein. Functional studies of alanine scanning mutants will be performed to achieve the objectives of Aim 1.
For Aim 2, co-transfection in cells lacking the stimulatory G protein will be used to probe the contact sites between the MC3R and the stimulatory G protein. The results of these studies will advance our understanding of the mechanisms of the MC3R coupling to the stimulatory G protein. They should also be of great interest for the GPCR-G protein field in general, where detailed mapping of the contact sites between GPCRs and their cognate G proteins has rarely been done.Obesity is an epidemic in the US with enormous health, economic and social costs. Current pharmacotherapies are far from ideal in terms of both efficacy and side effect. Our long-term goal is to exploit the melanocortin system as a novel approach for obesity treatment. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Academic Research Enhancement Awards (AREA) (R15)
Project #
1R15DK077213-01A2
Application #
7456268
Study Section
Molecular and Cellular Endocrinology Study Section (MCE)
Program Officer
Hyde, James F
Project Start
2008-05-01
Project End
2012-04-30
Budget Start
2008-05-01
Budget End
2012-04-30
Support Year
1
Fiscal Year
2008
Total Cost
$219,000
Indirect Cost
Name
Auburn University at Auburn
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
066470972
City
Auburn University
State
AL
Country
United States
Zip Code
36849
Yang, Li-Kun; Tao, Ya-Xiong (2017) Biased signaling at neural melanocortin receptors in regulation of energy homeostasis. Biochim Biophys Acta Mol Basis Dis 1863:2486-2495
Yang, Z; Tao, Y-X (2016) Mutations in Melanocortin-3 Receptor Gene and Human Obesity. Prog Mol Biol Transl Sci 140:97-129
Yang, Fan; Huang, Hui; Tao, Ya-Xiong (2015) Biased signaling in naturally occurring mutations in human melanocortin-3 receptor gene. Int J Biol Sci 11:423-33
Yang, Zhao; Huang, Zhi-Li; Tao, Ya-Xiong (2015) Functions of DPLIY motif and helix 8 of human melanocortin-3 receptor. J Mol Endocrinol 55:107-17
Mo, Xiu-Lei; Yang, Zhao; Tao, Ya-Xiong (2014) Targeting GPR119 for the potential treatment of type 2 diabetes mellitus. Prog Mol Biol Transl Sci 121:95-131
Tao, Ya-Xiong (2014) Constitutive activity in melanocortin-4 receptor: biased signaling of inverse agonists. Adv Pharmacol 70:135-54
Huang, Hui; Tao, Ya-Xiong (2014) Functions of the DRY motif and intracellular loop 2 of human melanocortin 3 receptor. J Mol Endocrinol 53:319-30
Huang, Hui; Dai, Meng-Hong; Tao, Ya-Xiong (2014) Physiology and therapeutics of the free fatty acid receptor GPR40. Prog Mol Biol Transl Sci 121:67-94
Tao, Ya-Xiong; Conn, P Michael (2014) Chaperoning G protein-coupled receptors: from cell biology to therapeutics. Endocr Rev 35:602-47
Tao, Ya-Xiong; Liang, Xu-Fang (2014) G protein-coupled receptors as regulators of glucose homeostasis and therapeutic targets for diabetes mellitus. Prog Mol Biol Transl Sci 121:1-21

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