Molecular characterization of angiotensin II type II receptors in rat pheochromocytoma cells
| Autor: | Christopher J. Molloy, Maria L. Webb, Hossain Monshizadegan, Robert Cohen, Elizabeth A. Bogosian, Suzanne Moreland, Randy Serafino, Kenneth E.J. Dickinson, T.J. Murphy, Eddie C.-K. Liu, Anders Hedberg |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Sarcosine
Physiology Population Adrenal Gland Neoplasms DNA Single-Stranded Pheochromocytoma Biology Phosphatidylinositols Biochemistry Angiotensin Receptor Antagonists Cellular and Molecular Neuroscience chemistry.chemical_compound Endocrinology Cyclic AMP Tumor Cells Cultured Animals RNA Messenger Phosphorylation Binding site Receptor education Cyclic GMP education.field_of_study Arachidonic Acid Receptors Angiotensin Angiotensin II Cell Membrane Nucleic Acid Hybridization Proteins Molecular biology Rats Dissociation constant chemistry Calcium Signal transduction hormones hormone substitutes and hormone antagonists Signal Transduction |
| Zdroj: | Peptides. 13:499-508 |
| ISSN: | 0196-9781 |
| DOI: | 10.1016/0196-9781(92)90081-d |
| Popis: | The binding sites and biochemical effects of angiotensin (A) II were investigated in rat pheochromocytoma (PC12W) cells. Sarcosine1, [125I]-tyrosine4, isoleucine8-AII ([125I]-SI-AII) bound to a saturable population of sites on membranes with an equilibrium dissociation constant (Kd) of 0.4 nM and a binding site maximum of 254 fmol/mg protein. Competitive displacement of [125I]-SI-AII by agonists and antagonists elucidated a rank order of potency of AIII greater than or equal to AII greater than PD 123177 greater than AI greater than [des-Phe]AII [AII(1-7)] much greater than DuP 753. The stable guanine nucleotide analog 5'-guanylyl imidodiphosphate did not alter the binding affinity or slope of the inhibition curves for AI, AII, AIII, or AII(1-7). Treatment of PC12W cells with AII or AIII did not affect the free intracellular calcium concentration, phosphoinositide metabolism, arachidonate release, cyclic GMP, or cyclic AMP concentrations. [125I]-AII binding sites remained on the cell surface and were not internalized after 2 h at 37 degrees C. Angiotensin II did not stimulate tyrosine, serine, or threonine phosphorylation. Northern analysis of PC12W mRNA with an AT1 receptor gene probe failed to produce an RNA:DNA hybrid at low stringency. These data indicate that PC12W cells express a homogeneous population of AT2 binding sites which differ significantly from AT1 receptors in signal transduction and molecular structure. AT2 sites may act via potentially novel, biochemical pathways or, alternatively, be vestigial receptors. |
| Databáze: | OpenAIRE |
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