Open AccessRegulation of EGF‐induced ERK/MAPK Activation and EGFR Internalization by G Protein‐coupled Receptor Kinase 2
Author(s) -
GAO Jingxia,
LI Jiali,
MA Lan
Publication year - 2005
Publication title -
acta biochimica et biophysica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.771
H-Index - 57
eISSN - 1745-7270
pISSN - 1672-9145
DOI - 10.1111/j.1745-7270.2005.00076.x
Subject(s) - internalization , mapk/erk pathway , beta adrenergic receptor kinase , microbiology and biotechnology , g protein coupled receptor kinase , epidermal growth factor , g protein coupled receptor , kinase , chemistry , signal transduction , biology , receptor , biochemistry
G protein‐coupled receptor kinases (GRKs) mediate agonist‐induced phosphorylation and desensitization of various G protein‐coupled receptors (GPCRs). We investigate the role of GRK2 on epidermal growth factor (EGF) receptor signaling, including EGF‐induced extracellular signal‐regulated kinase and mitogen‐activated protein kinase (ERK/MAPK) activation and EGFR internalization. Immunoprecipitation and immunofluorescence experiments show that EGF stimulates GRK2 binding to EGFR complex and GRK2 translocating from cytoplasm to the plasma membrane in human embryonic kidney 293 cells. Western blotting assay shows that EGF‐induced ERK/MAPK phosphorylation increases 1.9‐fold, 1.1‐fold and 1.5‐fold ( P <0.05) at time point 30, 60 and 120 min, respectively when the cells were transfected with GRK2, suggesting the regulatory role of GRK2 on EGF‐induced ERK/MAPK activation. Flow cytometry experiments show that GRK2 overexpression has no effect on EGF‐induced EGFR internalization, however, it increases agonist‐induced G protein‐coupled δ opioid receptor internalization by approximately 40% ( P <0.01). Overall, these data suggest that GRK2 has a regulatory role in EGF‐induced ERK/MAPK activation, and that the mechanisms underlying the modulatory role of GRK2 in EGFR and GPCR signaling pathways are somewhat different at least in receptor internalization. Edited by
Lin LI