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Modulation of α 2C ‐Adrenergic Receptor Traffic by Molecular Chaperones
Author(s) -
Filipeanu Catalin
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.945.1
Subject(s) - calreticulin , receptor , calnexin , hek 293 cells , chemistry , microbiology and biotechnology , transfection , immunoprecipitation , biophysics , transient receptor potential channel , biology , biochemistry , gene , endoplasmic reticulum
Cold exposure stimulates a 2C ‐adrenergic receptor (a 2C ‐AR) transport to the cell surface leading to exaggerated vasoconstriction observed in Raynaud Phenomenon. To determine the molecular mechanisms underlying this effect, the a 2C ‐AR interactions with molecular chaperones were investigated by co‐immunoprecipitation in transfected HEK293T cells. The receptor interactions with calnexin and calreticulin were similar at 37 o C and at 30 o C. In contrast, exposure to 30 o C for 18 h decreased the a 2C ‐AR interactions with BiP/GRP78 (43 ± 11 %, n=3), suggesting that such prolonged interactions at 37 o C may delay the receptor transport. Further, low‐temperature decreased a 2C ‐AR interactions with with β‐COP (32 ± 9%, n=4), indicating that the retrograde traffic also prevented receptor traffic. Overexpression of BiP prevented the cold‐induced enhancement in α 2C ‐AR traffic, as determined by radio‐ligand binding. These data indicate that low‐temperature stimulates α 2C ‐AR transport to the cell surface by decreasing the receptor interactions with specific molecular chaperones. Thus, BiP and β‐COP might be useful biomarkers to detect the individuals susceptible to Raynaud Phenomenon. Supported by NIH Grant 2P20RR018766‐06.