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Characterization of the carboxyl terminal‐truncated endothelin B receptor coexpressed with G protein‐coupled receptor kinase 2
Author(s) -
Shibasaki Tadao,
Moroi Kayoko,
Nishiyama Mariko,
Zhou Jing,
Sakamoto Aiji,
Masaki Tomoh,
Ito Kazumitsu,
Haga Tatsuya,
Kimura Sadao
Publication year - 1999
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549900201613
Subject(s) - beta adrenergic receptor kinase , phosphorylation , microbiology and biotechnology , receptor , kinase , agonist , biology , endothelin receptor , g protein coupled receptor kinase , chemistry , biochemistry , g protein coupled receptor
The role of phosphorylation of the C‐terminal tail of endothelin B receptor (ETbR) in agonist‐induced desensitization was investigated, using a mutant lacking C‐terminal 40 amino acids (Δ40 ETbR). In cells expressing the wild type or Δ40 ETbR, ET‐1 caused rapid desensitization of calcium responses. The wild type ETbR was phosphorylated by biotinylated ET‐1, and the phosphorylation was markedly enhanced by coexpression with G protein‐coupled receptor kinase 2 (GRK2). However, Δ40 ETbR was not phosphorylated regardless of coexpression with GRK2. On the other hand, ET‐1‐induced IP3 formation in these cells was decreased by coexpression with GRK2 or catalytically inactive Lys220Arg GRK2 to the similar extent. The present study demonstrates the presence of phosphorylation‐independent desensitization mechanism in Δ40 ETbR and suggests that GRK2 might play a role other than that as a kinase.