Neuroblastoma (NB) cell lines have served as models in the study of opioid receptor structure and function; however, the presence of Delta sites only limited their value as a general model of the opioid receptor system. Screening in my laboratory of several human NB cells revealed the presence of Mu sites on at least one line, MC-NB-1, while Delta sites were expressed in several lines. The present project proposes to establish a number of suitable cell lines that express all of the major opioid receptor types and possibly subtypes. This will be accomplished by screening more existing NB lines, subcloning lines of interest, and producing somatic human-rodent cell hybrids. The latter can serve to localize the opioid receptor genes to specific chromosomes and to obtain hybrids with faster growth rates or higher receptor yield. Further, NB cell lines will be differentiated into mature neurons by several agents in order to study the regulation of opiate receptor expression. Special emphasis of the project will be placed on developing quantitative assays for the opioid receptor molecules, including detection with biotinylated Beta-endorphin and monoclonal antibodies in conjunction with immunochemical techniques (fluorescence, enzyme labels). These assays will be applied to fluorescence flow cytometry to determine receptor expression of single cells under various conditions (cell cycle phases, down-regulation, differentiation). In conjunction with fluorescence resonance energy transfer (e.g. fluorescein-labeled Mu receptor as donors and rhodamine labeled Delta receptors as acceptors), one can measure the average distance among receptor sites on a molecular scale (less than 100 Angstrom). This approach will be used to address the question of any physical association between Mu and Delta sites that are expressed on the same cell. Another important aspect of the proposal involves the question as to which second messengers are affected by the opioid receptors. We will concentrate on cAMP metabolism, phosphatidyl inositol turnover, and catechol metabolism and secretion, as well as CA++ disposition. Further, cell lines with high receptor yield will serve to solubilize and purify the opioid receptor types. One subsequent goal will include the production of a panel of monoclonal antibodies with varying epitope specificities. Finally, the current project will serve to foster a series of collaborative studies that have been initiated to elucidate the molecular biology of the opioid receptor system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA004166-02
Application #
3209412
Study Section
(DABB)
Project Start
1986-08-01
Project End
1989-07-31
Budget Start
1987-08-01
Budget End
1988-07-31
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Type
Schools of Pharmacy
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
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Zhang, Ying; Wang, Danxin; Sadee, Wolfgang (2005) Calmodulin interaction with peptides from G-protein coupled receptors measured with S-Tag labeling. Biochem Biophys Res Commun 333:390-5
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Wang, Danxin; Raehal, Kirsten M; Lin, Emil T et al. (2004) Basal signaling activity of mu opioid receptor in mouse brain: role in narcotic dependence. J Pharmacol Exp Ther 308:512-20
Quillan, J Mark; Carlson, Kurt W; Song, Chunyan et al. (2002) Differential effects of mu-opioid receptor ligands on Ca(2+) signaling. J Pharmacol Exp Ther 302:1002-12
Lin, Kedan; Wang, Danxin; Sadee, Wolfgang (2002) Serum response factor activation by muscarinic receptors via RhoA. Novel pathway specific to M1 subtype involving calmodulin, calcineurin, and Pyk2. J Biol Chem 277:40789-98
Wang, D; Raehal, K M; Bilsky, E J et al. (2001) Inverse agonists and neutral antagonists at mu opioid receptor (MOR): possible role of basal receptor signaling in narcotic dependence. J Neurochem 77:1590-600

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