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Interaction with Grb14 results in site‐specific regulation of tyrosine phosphorylation of the insulin receptor
Author(s) -
Nouaille Sébastien,
Blanquart Christophe,
Zilberfarb Vladimir,
Boute Nicolas,
Perdereau Dominique,
Roix Johan,
Burnol AnneFrançoise,
Issad Tarik
Publication year - 2006
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.7400668
Subject(s) - dephosphorylation , insulin receptor , phosphorylation , protein tyrosine phosphatase , biology , tyrosine phosphorylation , tyrosine , irs2 , biochemistry , receptor tyrosine kinase , microbiology and biotechnology , phosphatase , chemistry , insulin , endocrinology , insulin resistance
The dynamics of interaction of the insulin receptor (IR) with Grb14 was monitored, in real time, in living human embryonic kidney cells, using bioluminescence resonance energy transfer (BRET). We observed that insulin rapidly and dose‐dependently stimulated this interaction. We also observed that insulin‐induced BRET between the IR and protein tyrosine phosphatase 1B (PTP1B) was markedly reduced by Grb14, suggesting that Grb14 regulated this interaction in living cells. Using site‐specific antibodies against phosphorylated tyrosines of the IR, we showed that Grb14 protected the three tyrosines of the kinase loop from dephosphorylation by PTP1B, while favouring dephosphorylation of tyrosine 972. This resulted in decreased IRS‐1 binding to the IR and decreased activation of the extracellular signal‐regulated kinase pathway. Increased Grb14 expression in human liver‐derived HuH7 cells also seemed to specifically decrease the phosphorylation of Y972. Our work therefore suggests that Grb14 may regulate signalling through the IR by controlling its tyrosine dephosphorylation in a site‐specific manner.