Cloning and Functional Characterization of a σ Receptor from Rat Brain
| Autor: | Vadivel Ganapathy, Frederick H. Leibach, Pankaj Seth, You-Jun Fei, Hui W. Li, Wei Huang |
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| Rok vydání: | 2002 |
| Předmět: |
Narcotics
Clorgyline Pentazocine DNA Complementary Placenta Molecular Sequence Data Sigma receptor Gene Expression Biology Binding Competitive Guanidines Biochemistry Cellular and Molecular Neuroscience Complementary DNA Gene expression Animals Humans Receptors sigma Amino Acid Sequence Choriocarcinoma RNA Messenger Northern blot Cloning Molecular Receptor Peptide sequence Gene Library Brain Chemistry Messenger RNA Base Sequence Molecular biology Antidepressive Agents Rats Kinetics Liver Phenytoin Dopamine Antagonists Haloperidol Anticonvulsants Steroids Heterologous expression HeLa Cells |
| Zdroj: | Journal of Neurochemistry. 70:922-931 |
| ISSN: | 1471-4159 0022-3042 |
| DOI: | 10.1046/j.1471-4159.1998.70030922.x |
| Popis: | We have cloned a sigma receptor from rat brain and established its functional identity using a heterologous expression system. The cloned cDNA (1,582 bp long) codes for a protein of 223 amino acids that possesses a single putative transmembrane domain. The amino acid sequence of the rat brain sigma receptor is highly homologous to that of the sigma receptor recently cloned from guinea pig liver and a human placental cell line but is not related to any other known mammalian receptors. When expressed in HeLa cells, the rat brain sigma receptor cDNA leads to a two- to threefold increase in haloperidol binding, and this cDNA-induced binding is sensitive to inhibition by several sigma receptor-specific ligands. Kinetic analysis using the heterologous expression system has revealed that the rat brain sigma receptor interacts with haloperidol with an apparent dissociation constant (K(D)) of 3 nM. Functional expression of the cloned rat brain sigma receptor in HeLa cells also leads to an increase in the binding of two other sigma ligands, namely, (+)-pentazocine and (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine (PPP). Pharmacological characterization of the cloned rat brain sigma receptor reveals that it exhibits severalfold higher affinity for clorgyline than for 1 ,3-di(2-tolyl)guanidine, it interacts with progesterone and testosterone, and its interaction with PPP is markedly enhanced by phenytoin. In addition, transfection of MCF-7 cells, which do not express type 1 sigma receptor mRNA or activity, with the cloned rat brain cDNA leads to the appearance of haloperidol-sensitive binding of (+)-pentazocine, a selective type 1 sigma receptor ligand. These data show that the cloned rat brain cDNA codes for a functional type 1 sigma receptor. Northern blot analysis with poly(A)+ RNA isolated from various rat tissues has indicated that the sigma receptor-specific transcript, 1.6 kb in size, is expressed abundantly in liver and moderately in intestine, kidney, brain, and lung. |
| Databáze: | OpenAIRE |
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