Regulation of the water channel aquaporin-1: isolation and reconstitution of the regulatory complex
| Autor: | Rania Abu-Hamdah, Marie L. Kelly, Aleksandar Jeremic, Alina Elena Ilie, Bhanu P. Jena, Won-Jin Cho, Sang-Joon Cho |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Erythrocytes
GTP' Lipid Bilayers Aquaporin Wasp Venoms GTP-Binding Protein alpha Subunits Gi-Go Aquaporins Microscopy Atomic Force Group II Phospholipases A2 Phospholipases A Body Water Chloride Channels Glyburide medicine Animals Hypoglycemic Agents Aminobenzoates ortho-Aminobenzoates Potassium Channels Inwardly Rectifying Aquaporin 1 Chemistry Secretory Vesicles Antibodies Monoclonal Potassium channel blocker Biological membrane Cell Biology General Medicine Zymogen granule Potassium channel Rats CLC-2 Chloride Channels Chlorobenzoates Electrophysiology Phospholipases A2 Biochemistry Cinnamates Mastoparan Liposomes Biophysics Intercellular Signaling Peptides and Proteins Silver Nitrate Peptides Signal Transduction medicine.drug |
| Zdroj: | Cell Biology International. 28:7-17 |
| ISSN: | 1065-6995 |
| DOI: | 10.1016/j.cellbi.2003.11.003 |
| Popis: | Aquaporins (AQP) are involved in rapid and active gating of water across biological membranes. The molecular regulation of AQP is unknown. Here we report the isolation, identification and reconstitution of the regulatory complex of AQP-1. AQP-1 and Galphai3 have been implicated in GTP-induced gating of water in zymogen granules (ZG), the secretory vesicles in exocrine pancreas. In the present study, detergent-solubilized ZGs immunoprecipitated with monoclonal AQP-1 antibody, co-isolates AQP-1, PLA2, Galphai3, potassium channel IRK-8, and the chloride channel ClC-2. Exposure of ZGs to either the potassium channel blocker glyburide, or the PLA2 inhibitor ONO-RS-082, blocked GTP-induced ZG swelling. RBC known to possess AQP-1 at the plasma membrane, swell on exposure to the Galphai-agonist mastoparan, and respond similarly to ONO-RS-082 and glyburide, as ZGs. Liposomes reconstituted with the AQP-1 immunoisolated complex from solubilized ZG, also swell in response to GTP. Glyburide or ONO-RS-082 abolished the GTP effect. Immunoisolate-reconstituted planar lipid bilayers demonstrate conductance, which is sensitive to glyburide and an AQP-1 specific antibody. Our results demonstrate a Galphai3-PLA2 mediated pathway and potassium channel involvement in AQP-1 regulation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text