Open AccessFeedback control of ErbB2 via ERK-mediated phosphorylation of a conserved threonine in the juxtamembrane domain
Author(s) -
Yuki Kawasaki,
Ayaka Sakimura,
Chul Min Park,
Rika Tomaru,
Tomohiro Tanaka,
Tatsuhiko Ozawa,
Yue Zhou,
Kaori Narita,
Hiroyuki Kishi,
Atsushi Muraguchi,
Hiroaki Sakurai
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep31502
Subject(s) - phosphorylation , mapk/erk pathway , tyrosine phosphorylation , erbb , phosphorylation cascade , threonine , erbb3 , microbiology and biotechnology , receptor tyrosine kinase , biology , kinase , tyrosine , chemistry , signal transduction , protein phosphorylation , biochemistry , serine , protein kinase a
Tyrosine kinase activity of the asymmetric EGFR homodimer is negatively regulated via ERK-mediated phosphorylation of Thr-669 in the juxtamembrane domain. In the present study, we investigated in human breast cancer cells whether a similar mechanism plays a role in the feedback regulation of the ErbB2/ErbB3 heterodimer, the most potent ErbB receptor dimer. Constitutive tyrosine phosphorylation of ErbB2 and ErbB3 was significantly decreased in phorbol ester- and growth factor-treated BT-474 and MDA-MB-453 cells. In contrast to the decreased tyrosine phosphorylation, Phos-tag Western blot analysis revealed that TPA induced phosphorylation of ErbB2 in an ERK-dependent manner. The target threonine residue corresponding to EGFR Thr-669 and the surrounding residues are highly conserved in ErbB2, but not in ErbB3. Therefore, we demonstrated ERK-mediated phosphorylation of ErbB2 at Thr-677 by generating phospho-specific monoclonal antibodies. Moreover, treatment with trametinib and SCH772984, inhibitors of the MEK-ERK pathway, and substitution of Thr-677 to alanine impaired the feedback inhibition of ErbB2 and ErbB3. These results demonstrated that ERK-mediated phosphorylation of the conserved threonine is a common mechanism for the negative feedback control of active ErbB receptor dimers.