TY - JOUR
T1 - Erythropoietin induces the association of phosphatidylinositol 3′‐kinase with a tyrosine‐phosphorylated protein complex containing the erythropoietin receptor
AU - MAYEUX, Patrick
AU - DUSANTER‐FOURT, Isabelle
AU - MULLER, Odile
AU - MAUDUIT, Philippe
AU - SABBAH, Michèle
AU - DRUKER, Brian
AU - VAINCHENKER, William
AU - FISCHER, Sigmund
AU - LACOMBE, Catherine
AU - GISSELBRECHT, Sylvie
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1993/9
Y1 - 1993/9
N2 - Stimulation of sensitive cells with erythropoietin results in rapid induction of protein tyrosine phosphorylation. Other than tyrosine phosphorylation of one chain of the erythropoietin receptor, the identities of the remaining tyrosine‐phosphorylated proteins are undefined. In this report, we demonstrate that the stimulation of the erythropoietin‐sensitive human UT7 cells by erythropoietin rapidly resulted in the appearance of phosphatidylinositol 3‐kinase activity in anti‐phosphotyrosine immunoprecipitates. Erythropoietin action was rapid, detectable after as early as 1 min stimulation, transient, returning to control level after 30 min stimulation and was observed using the erythropoietin concentrations able to stimulate the cell proliferation. Anti‐(phosphatidylinositol 3‐kinase) antibodies specifically immunoprecipitated 125I‐erythropoietin bound to its receptor, strongly suggesting that phosphatidylinositol 3‐kinase associated with a protein complex containing the activated erythropoietin receptor. To confirm this result, phosphatidylinositol 3‐kinase was immunoprecipitated from erythropoietin‐stimulated cells using mild conditions followed by Western analysis using anti‐phosphotyrosine antibodies. Five tyrosine phosphorylated proteins were revealed: the cloned chain of the erythropoietin receptor, the regulatory subunit of phosphatidylinositol 3‐kinase and three unidentified proteins of 111, 97 and 64 kDa. None of these tyrosine phosphorylated proteins was detected in anti‐(phosphatidylinositol 3‐kinase) immunoprecipitates from unstimulated cells. Thus, our results show that phosphatidylinositol 3‐kinase associates with a tyrosine‐phosphorylated protein complex containing the activated erythropoietin receptor.
AB - Stimulation of sensitive cells with erythropoietin results in rapid induction of protein tyrosine phosphorylation. Other than tyrosine phosphorylation of one chain of the erythropoietin receptor, the identities of the remaining tyrosine‐phosphorylated proteins are undefined. In this report, we demonstrate that the stimulation of the erythropoietin‐sensitive human UT7 cells by erythropoietin rapidly resulted in the appearance of phosphatidylinositol 3‐kinase activity in anti‐phosphotyrosine immunoprecipitates. Erythropoietin action was rapid, detectable after as early as 1 min stimulation, transient, returning to control level after 30 min stimulation and was observed using the erythropoietin concentrations able to stimulate the cell proliferation. Anti‐(phosphatidylinositol 3‐kinase) antibodies specifically immunoprecipitated 125I‐erythropoietin bound to its receptor, strongly suggesting that phosphatidylinositol 3‐kinase associated with a protein complex containing the activated erythropoietin receptor. To confirm this result, phosphatidylinositol 3‐kinase was immunoprecipitated from erythropoietin‐stimulated cells using mild conditions followed by Western analysis using anti‐phosphotyrosine antibodies. Five tyrosine phosphorylated proteins were revealed: the cloned chain of the erythropoietin receptor, the regulatory subunit of phosphatidylinositol 3‐kinase and three unidentified proteins of 111, 97 and 64 kDa. None of these tyrosine phosphorylated proteins was detected in anti‐(phosphatidylinositol 3‐kinase) immunoprecipitates from unstimulated cells. Thus, our results show that phosphatidylinositol 3‐kinase associates with a tyrosine‐phosphorylated protein complex containing the activated erythropoietin receptor.
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U2 - 10.1111/j.1432-1033.1993.tb18203.x
DO - 10.1111/j.1432-1033.1993.tb18203.x
M3 - Article
C2 - 8404901
AN - SCOPUS:0027424082
SN - 0014-2956
VL - 216
SP - 821
EP - 828
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 3
ER -