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Caveolin‐1 affects serotonin binding and cell surface levels of human 5‐HT 7(a) receptors
Author(s) -
Sjögren Benita,
Svenningsson Per
Publication year - 2007
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2007.09.059
Subject(s) - receptor , 5 ht receptor , lipid raft , serotonin , chemistry , caveolae , caveolin 1 , cell surface receptor , clathrin , agonist , microbiology and biotechnology , cell , biochemistry , biology , endocytosis
Studies using HeLa cells expressing 5‐HT 7 receptors showed that detergent resistant membranous lipid rafts purified by sucrose gradient centrifugation contained 5‐HT 7 receptors and caveolin‐1. Caveolin‐1 siRNA‐mediated knockdown or serotonin (5‐HT) treatment caused significant reductions of maximum [ 3 H]5‐HT binding to 5‐HT 7 receptors and total immunoreactivity of membranous 5‐HT 7 receptors in intact cells. Co‐treatment with 5‐HT, caveolin‐1 siRNA and methyl‐β‐cyclodextrin had no additive effects on reducing maximum binding of [ 3 H]5‐HT to 5‐HT 7 receptors. 5‐HT‐mediated reduction of [ 3 H]5‐HT binding to 5‐HT 7 receptors was counteracted by genistein, but not by sucrose. Caveolin‐1, specifically localized in cholesterol‐enriched lipid rafts, appears to regulate constitutive and agonist‐stimulated cell surface levels of 5‐HT 7 receptors via a clathrin‐independent mechanism.