NIDA - Director's Report - September, 2010 NIDA Home > Publications > Director's Reports Director's Report to the National Advisory Council on Drug Abuse - September, 2010 Report Index Index Report for September, 2010 Research Findings Report for May, 2010 Basic Neurosciences Research Report for February, 2010 Basic Behavioral Research Older Reports - go to the Archives Behavioral and Brain Development Research Clinical Neuroscience Research Epidemiology and Etiology Research Prevention Research NACDA Behavioral and Integrative Treatment Research Legislation Research on Pharmacotherapies for Drug Abuse Research on Medical Consequences of Drug Abuse and Co-Occurring Infections (HIV/AIDS, HCV) Services Research Clinical Trials Network Research Intramural Research Program Activities Extramural Policy and Review Activities Congressional Affairs International Activities Meetings and Conferences Media and Education Activities Planned Meetings Publications Staff Highlights Grantee Honors https://archives.drugabuse.gov/DirReports/DirRep910/[11/17/16, 11:34:51 PM] NIDA - Director's Report - September, 2010 Archive Home | Accessibility | Privacy | FOIA (NIH) | Current NIDA Home Page The National Institute on Drug Abuse (NIDA) is part of the National Institutes of Health (NIH) , a component of the U.S. Department of Health and Human Services. Questions? _ See our Contact Information. https://archives.drugabuse.gov/DirReports/DirRep910/[11/17/16, 11:34:51 PM] NIDA - Director's Report - September, 2010 NIDA Home > Publications > Director's Reports Director's Report to the National Advisory Council on Drug Abuse - September, 2010 Report Index Index Report for September, 2010 Research Findings Report for May, 2010 Basic Neurosciences Research Report for February, 2010 Basic Behavioral Research Older Reports - go to the Archives Behavioral and Brain Development Research Clinical Neuroscience Research Epidemiology and Etiology Research Prevention Research NACDA Behavioral and Integrative Treatment Research Legislation Research on Pharmacotherapies for Drug Abuse Research on Medical Consequences of Drug Abuse and Co-Occurring Infections (HIV/AIDS, HCV) Services Research Clinical Trials Network Research Intramural Research Program Activities Extramural Policy and Review Activities Congressional Affairs International Activities Meetings and Conferences Media and Education Activities Planned Meetings Publications Staff Highlights Grantee Honors https://archives.drugabuse.gov/DirReports/DirRep910/default.html[11/17/16, 11:34:56 PM] NIDA - Director's Report - September, 2010 Archive Home | Accessibility | Privacy | FOIA (NIH) | Current NIDA Home Page The National Institute on Drug Abuse (NIDA) is part of the National Institutes of Health (NIH) , a component of the U.S. Department of Health and Human Services. Questions? _ See our Contact Information. https://archives.drugabuse.gov/DirReports/DirRep910/default.html[11/17/16, 11:34:56 PM] NIDA - Director's Report - September, 2010 NIDA Home > Publications > Director's Reports > September, 2010 Index Director's Report to the National Advisory Council on Drug Abuse - September, 2010 Index Research Findings - Basic Neuroscience Research Research Findings RGS9-2 Signaling Partners Basic Neurosciences Research Regulators of G protein signaling (RGS) are known to bind to G alpha proteins, Basic Behavioral Research speeding the process of GTP hydrolysis and terminating the signaling pathway in which the GPCR participates. Based on immunoblotting and Behavioral and Brain immunoprecipitation results, the RGS9-2 protein, highly expressed in the Development Research striatum and nucleus accumbens, forms a tertiary complex with the G protein Clinical Neuroscience Gbeta5, and with R7BP (R7 binding protein) at distinct binding regions of Research RGS9-2. Certain details about the stoichiometry of this complex are Epidemiology and Etiology understood: Gbeta5 is necessary for the constitutive expression of RGS9-2, Research and these two partners are expressed in direct proportion, i.e., both their expression levels increase, or decrease together, as in the case of R7BP being Prevention Research absent in a R7BP knockout mouse species. The binding of R7BP may aid in Behavioral and Integrative targeting RGS9-2 to post-synaptic neuronal regions, and may also contribute to Treatment Research the stability of the RGS9-2/Gbeta5 complex. RGS9-2 has been studied as a Research on regulator of dopamine and opioid (mu receptor) signaling in the animal brain. Pharmacotherapies for Drug RGS9-2 levels are decreased in rats chronically self-administering cocaine, and Abuse RGS9-2 knockout mice have increased sensitivity to the rewards of morphine (lower doses) in place conditioning experiments, compared to wild type mice. Research on Medical RGS9-2 knockout mice show enhanced withdrawal symptoms following Consequences of Drug morphine administration. Dr. Martemyanov and his associates at the University Abuse and Co-Occurring of Minnesota have carried out a quantitative proteomics study to detect Infections (HIV/AIDS, HCV) changes in the proteins that complex to RGS9-2 when R7BP is absent, using Services Research the R7BP knockout mouse. Three striatal brain samples were used: a wild type, Clinical Trials Network an R7BP knockout sample, and, for control purposes, an RGS9-2 knockout Research sample to detect non-specific interactions in the absence of RGS9-2. Following Intramural Research immunoprecipitation to obtain proteins from the samples, each sample was treated with trypsin to produce fragment peptides, which were derivatized with Program Activities three different isotopically-labeled tags, samples were combined, separated by LC, and analyzed by mass spectrometry. RGS9-2 interaction with Gbeta5 was Extramural Policy and confirmed, and, in the absence of R7BP in the complex, twenty-one new Review Activities binding partners of RGS9-2 were identified as being upregulated, including the heat shock chaperone protein Hsc70. Hsc70 was absent (no Congressional Affairs immunoprecipitation) in RGS9-2 knockout samples, and in R7BP knockout striatal tissue, increasing in amount when R7BP was absent. The binding of International Activities Hsc70 protein was found to take place at a C-terminus peptide fragment of RGS9-2. When Hsc70 was "silenced" by siRNA for Hsc70, the RGS9-2 Meetings and Conferences expression increased 17%, based on Western blotting analysis. Therefore, Hsc70 negatively regulated the RGS9-2 expression. Although the mechanism of Media and Education Hsc70 action is not known presently, Hsc70 may serve to regulate RGS9-2 by Activities targeting a RGS9-2 complex into lysosomes, where it can be degraded. Posokhova E, Uversky V, Martemyanov KA. Proteomic identification of Hsc70 as Planned Meetings a mediator of RGS9-2 degradation by in vivo interactome analysis. J Proteome https://archives.drugabuse.gov/DirReports/DirRep910/DirectorReport1.html[11/17/16, 11:35:00 PM] NIDA - Director's Report - September, 2010 Res 2010; 9(3): 1510-1521. Publications Negative Allosteric Modulators that Target Human α4β2 Neuronal Staff Highlights Nicotinic Receptors Grantee Honors Allosteric modulation of nicotinic acetylcholine receptors (nAChRs) is considered to be one of the most promising approaches for therapeutics. The present authors previously reported on the pharmacological activity of several compounds that acted as negative allosteric modulators (NAMs) of nAChRs. In this publication the effects of 30 NAMs from the authors' small chemical library on both human α4β2 (Hα4β2) nAChRs and human α3β4 (Hα3β4) nAChRs expressed in HEK ts201 cells were investigated. Using calcium accumulation assays, these NAMs inhibited nAChRs activation with IC50 values ranging from 2.4 µM to greater than 100 µM. Several NAMs showed relative selectivity for Hα4β2 nAChRs with IC50 values in the low micromolar range. A lead molecule, KAB-18 was identified that showed relative selectivity for Hα4β2 nAChRs. This molecule contains 3-phenyl rings, 1 piperidine ring, and 1 ester bond linkage. Structure-activity relationship (SAR) analyses revealed 3 regions of KAB-18 that contributed to its relative selectivity. Predictive 3D-QSAR (comparative molecular field analysis and comparative molecular similarity indices analysis) models were generated from these data and a pharmacophore model was constructed to determine the chemical features that were important for biological activity. Using docking approaches and molecular dynamics on Hα4β2 nAChR homology model, a binding mode for KAB-18 at the α/β sub-unit interface that corresponded to the predicted pharmacophore was described. This binding study was supported by mutagenesis studies. In summary, these studies highlight the importance of SAR, computational, and molecular biology approaches for the design and synthesis of potent and selective antagonists targeting specific nAChR sub-types. Henderson BJ, Pavlovicz RE, Allen JD, Gonzalez-Cestari TF, Orac CM, Bonnell AB, Zhu MX, Thomas Boyd R, Li C, Bergmeier SC, McKay DB. Negative Allosteric Modulators that Target Human α4β2 Neuronal Nicotinic Receptors, J Pharmacol Exp Ther. 2010, Jun 15. [Epub ahead of print]. Molecular Mechanisms Involving Cocaine/Sigma Receptor- Mediated Induction of MCP-1: Implication For Increased Monocyte Transmigration Cocaine abuse hastens the neurodegeneration often associated with advanced HIV-1infection. The mechanisms, in part, revolve around the neuroinflammatory processes mediated by the chemokine monocyte chemotactic protein-1 (MCP-1/CCL2).