Suleiman W. Bahouth, Ph.D.
Department of Pharmacology
The University of Tennessee
Health Science Center
Department of Medicine, Division of Cardiovascular Diseases
874 Union Avenue
Memphis, TN 38163
Phone: (901) 448-6009
Fax: (901) 448-7300
Lab: 309 Crowe Research Building
Email: Suleiman W. Bahouth
- Ph.D. Institution: New York University, Department of Pharmacology
- Postdoctoral: State University of New York at Stony Brook, Department of Molecular Pharmacology
My research program is focused on analyzing the mechanism(s) by which hormones and neurotransmitters regulate transmembranal signalling. The approach involves determining the regions in G protein coupled receptors and GTP binding regulatory proteins (G proteins) that are involved in regulating the sensitivity of the cell to hormones and neurotransmitters.
The sensitivity of the heart to the neurotransmitter norepinephrine or to its circulating counterpart epinephrine, is profoundly influenced by thyroid hormones (T3). In the heart, it appears that the dominant receptor mediating the functions of catecholamines is the beta-adrenergic receptor. T3 upregulate the number of beta-adrenergic receptors in the heart cell and increase their sensitivity to catecholamines. With respect to the receptor, T3 exert their effects by increasing the transcription of the beta-adrenergic receptor gene. The goal of our ongoing studies is to identify the cis-acting DNA sequences in the beta-adrenergic receptor gene and trans-acting nuclear proteins that are involved in the stimulation of beta-adrenergic receptor gene transcription by T3.
The sensitivity of the receptor to catecholamines is modulated by T3 through a complex mechanism operating at a point distal to the receptor. Activation of the beta-adrenergic receptor results in the initiation of a cascade that results in the generation of the intracellular messenger cyclic AMP. The activity of the effector enzyme that catalyzes the conversion of ATP to cyclic AMP is regulated by G proteins. Our studies are focused on identifying the mechanism by which T3 regulate the abundance and coupling of G proteins to the receptor and effector.
- Hajjhussein H, Gardner LA, Fujii N, Anderson NM, Bahouth SW. The hydrophobic amino acid cluster at the cytoplasmic end of transmembrane helix III modulates the coupling of the Î²(1)-adrenergic receptor to G(s). J Recept Signal Transduct Res. 2013 Apr;33(2):79-88. doi: 10.3109/10799893.2012.759590. Epub 2013 Jan 25. PubMed PMID: 23351074.
- Sacks HS, Fain JN, Cheema P, Bahouth SW, Garrett E, Wolf RY, Wolford D, Samaha J. Depot-specific overexpression of proinflammatory, redox, endothelial cell, and angiogenic genes in epicardial fat adjacent to severe stable coronary atherosclerosis. Metab Syndr Relat Disord. 2011 Dec;9(6):433-9. doi: 10.1089/met.2011.0024. Epub 2011 Jun 16. PubMed PMID: 21679057.
- Sacks HS, Fain JN, Cheema P, Bahouth SW, Garrett E, Wolf RY, Wolford D, Samaha J. Inflammatory genes in epicardial fat contiguous with coronary atherosclerosis in the metabolic syndrome and type 2 diabetes: changes associated with pioglitazone. Diabetes Care. 2011 Mar;34(3):730-3. doi: 10.2337/dc10-2083. Epub 2011 Feb 2. PubMed PMID: 21289232; PubMed Central PMCID: PMC3041217.
- Company JM, Booth FW, Laughlin MH, Arce-Esquivel AA, Sacks HS, Bahouth SW, Fain JN. Epicardial fat gene expression after aerobic exercise training in pigs with coronary atherosclerosis: relationship to visceral and subcutaneous fat. J Appl Physiol. 2010 Dec;109(6):1904-12. doi: 10.1152/japplphysiol.00621.2010. Epub 2010 Oct 14. PubMed PMID: 20947714; PubMed Central PMCID: PMC3006413.
- Gardner LA, Hajjhussein H, Frederick-Dyer KC, Bahouth SW. Rab11a and its binding partners regulate the recycling of the ÃŸ1-adrenergic receptor. Cell Signal. 2011 Jan;23(1):46-57. doi: 10.1016/j.cellsig.2010.07.020. Epub 2010 Aug 18. PubMed PMID: 20727405; PubMed Central PMCID: PMC2956792.
- Fain JN, Sacks HS, Bahouth SW, Tichansky DS, Madan AK, Cheema PS. Human epicardial adipokine messenger RNAs: comparisons of their expression in substernal, subcutaneous, and omental fat. Metabolism. 2010 Sep;59(9):1379-86. doi: 10.1016/j.metabol.2009.12.027. Epub 2010 Feb 1. PubMed PMID: 20116810.