Faculty: Arnold E. Ruoho, PhD
|Dept:||Professor, Dept. of Neuroscience|
|Contact:|| 4775A MSC
The effort in my laboratory is directed at an understanding of the molecular mechanisms which underlie neurotransmitter release and receptor activation. Several families of proteins which are of specific biochemical interest to us are: (a)beta-adrenergic receptors and rhodopsin, (b) GTP binding proteins, (c) catecholamine transport proteins and (d) sigma receptors.
Projects to identify structural and functional domains of adrenergic receptors and G proteins include: (a) intermolecular interactions between G-proteins and receptors; (b) identification of the G-protein a-subunit interaction domain with effectors, such as the enzyme, adenylyl cyclase, and the g-subunit of cGMP phosphodiesterase; and (c) the three-dimensional structure of active domains of the G-protein-inked receptors and adenylyl cyclase using NMR and crystallography approaches. These experiments utilize multiple methodological approaches, including baculovirus expression of receptors, synthesis and use of agonist and antagonist photoaffinity labels, and the application of "tethered" photoactivatable molecules to probe G-protein structure and nearest neighbor interactions.
Two types of catecholamine transport proteins are being characterized: (a) the storage vesicle transporter, which is inhibited by the drug reserpine; and (b) the plasma membrane transporter, which is inhibited by drugs of abuse, such as cocaine. Molecular properties of the transporters are being determined using radioiodinated reserpine and cocaine photoaffinity labels, purification and cloning, PCR amplication of transporter sequences, and stable expression of transporters in cultured cell lines, such as HeLa, COS, and CHO. The plasma membrane transporters are targets for drugs which are used to treat depression, targets for drugs of abuse, such as cocaine, and may be involved in the etiology of schizophrenia. The sigma receptor is a mammalian protein with multiple putative functions in the brain and the periphery. We have demonstrated that calcium-activiated potassium channels are inhibited by sigma receptors and that these receptors are enriched in cancer cells. Our goal is to identify the natural ligands for the sigma receptor, characterize the binding site, and determine the role of the sigma receptor in intracellular signaling.
A student in my laboratory will receive training on the molecular pharmacology of neurotransmitter mechanisms, membrane protein purification, synthesis and use of photoaffinity labels, and applications of molecular biology to the study of receptors, G proteins, effectors, and transporters.
Honors & Awards
- 1998-2003 WARF/University Houses Name Professorship
- 1997 - Co-Awardee, Gold Crystal Award (First Place), Molecular Structure Corporation, Houston , Texas
- McPherson Eye Research Institute
- Mavlyutov TA, Epstein ML, Verbny YI, Huerta MS, Zaitoun I, Ziskind-Conhaim L, and Ruoho AE (2013). Lack of sigma-1 receptor exacerbates ALS progression in mice. Neuroscience. 240:129-34. Epub 2013 Feb 28
- Chu UB, Ramachandran S, Hajipour AR,and Ruoho AE (2013). Photoaffinity Labeling of the Sigma-1 Receptor with N-[3-(4-Nitrophenyl)propyl]-N-dodecylamine: Evidence of Receptor Dimers. Biochemistry. 52:859-868. Epub 2013 Jan 28. PMID: 23324054
- Guo LW, Hajipour AR, Karaoglu K, Mavlyutov TA,and Ruoho AE (2012). Development of benzophenone-alkyne bifunctional sigma receptor ligands.Chembiochem. 13:2277-2289. Epub 2012 Sep 23. PMID: 23001760
- Pal A, Fontanilla D, Gopalakrishnan A, Chae YK, Markley JL, and Ruoho AE (2012). The sigma-1 receptor protects against cellular oxidative stress and activates antioxidant response elements. Eur J Pharmacol. 682:12-20. PMID: 22381068
- Ruoho AE, Chu UB, Ramachandran S, Fontanilla D, Mavlyutov T, and Hajipour AR (2012). The Ligand Binding Region of the Sigma-1 Receptor: Studies Utilizing Photoaffinity Probes, Sphingosine and N-alkylamines. Curr Pharm Des. PMID: 22288412
- Mavlyutov TA, Epstein ML, Liu P, Verbny YI, Ziskind-Conhaim L, and Ruoho AE (2012). Development of the sigma-1 receptor in C-terminals of motoneurons and colocalization with the N,N'-dimethyltryptamine forming enzyme, indole-N-methyl transferase. Neuroscience. 206:60-68. PMID: 22265729
- Guo LW and Ruoho AE (2011). N-terminal half of the cGMP phosphodiesterase gamma-subunit contributes to stabilization of the GTPase-accelerating protein complex. J Biol Chem. 286(17):15260-7. PMID: 21393250
- Johannessen M, Fontanilla D, Mavlyutov T, Ruoho AE, and Jackson MB (2011). Antagonist action of progesterone at √-receptors in the modulation of voltage-gated sodium channels. Am J Physiol Cell Physiol. 300:C328-37. PMID: 21084640
- Su TP, Hayashi T, Maurice T, Buch S, and Ruoho AE (2010). The sigma-1 receptor chaperone as an inter-organelle signaling modulator. Trends Pharmacol Sci. 31:557-66. Epub 2010 Oct 1. PMID: 20869780
- Mavlyutov TA, Epstein ML, Andersen KA, Ziskind-Conhaim L, and Ruoho AE (2010). The sigma-1 receptor is enriched in postsynaptic sites of C-terminals in mouse motoneurons. An anatomical and behavioral study. Neuroscience. 167:247-55. Epub 2010 Feb 16. PMID: 20167253
- Johannessen M, Ramachandran S, Riemer L, Ramos-Serrano A, Ruoho AE, and Jackson MB (2009). Voltage-gated sodium channel modulation by sigma-receptors in cardiac myocytes and heterologous systems. Am J Physiol Cell Physiol. 296:C1049-57. PMID: 19279232
- Fontanilla D, Johannessen M, Hajipour AR, Cozzi NV, Jackson MB, and Ruoho AE (2009). The hallucinogen N,N-dimethyltryptamine (DMT) is an endogenous sigma-1 receptor regulator. Science. 323:934-7. PMID: 19213917
- Guo LW and Ruoho AE (2008). The retinal cGMP phosphodiesterase gamma-subunit - a chameleon. Curr Protein Pept Sci. 9:611-25. Review. PMID: 19075750
- Mavlyutov TA and Ruoho AE (2007). Ligand-dependent localization and intracellular stability of sigma-1 receptors in CHO-K1 cells. J Mol Signal. 2:8 PMID 17883859
- Gopalakrishnan A, Sievert MK, and Ruoho AE (2007). Identification of the substrate binding region of VMAT-2 using Iodaminoflisopolol as a novel photoprobe. Mol Pharmacol. 72:1567-1575. PMID 17766642
- Pal A, Hajipour AR, Fontanilla D, Ramachandran S, Chu UB, Mavlyutov T, and Ruoho AE (2007). Identification of regions of the sigma-1 receptor ligand binding site using a novel photoprobe. Mol Pharmacol. 72:921-933. PMID 17622576
- Guo LW, Assadi-Porter FM, Grant JE, Wu H, Markley JL, and Ruoho AE (2007). One-step purification of bacterially expressed recombinant transducin alpha-subunit and isotopically labeled PDE6 gamma-subunit for NMR analysis. Protein Expr Purif. 51:187-197. PDF PMID 16938469