Nuclear translocation of insulin receptor substrate-1 by the insulin receptor in mouse embryo fibroblasts.
Translocation of the insulin receptor substrate-1 (IRS-1) to the nuclei has been reported to occur in cells stimulated by insulin-like growth factor-1 (IGF-I) or expressing certain viral and cellular oncogenes. We show here that insulin can also induce nuclear translocation of IRS-1 in mouse embryo fibroblasts (MEF), that do not express the type 1 insulin-like growth factor receptor (IGF-IR). Only the A isoform of the insulin receptor (IR) can induce IRS-1 nuclear translocation, which is significant when the receptor is over-expressed. At physiological receptor levels, translocation occurs only in a fraction of cells, and only at high concentrations of ligand.
Wu
An
A
Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Sciacca
Laura
L
Baserga
Renato
R
D021581:Active Transport, Cell Nucleus; D000818:Animals; D015703:Antigens, CD; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018390:Gene Targeting; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology; D055504:Insulin Receptor Substrate Proteins; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D051379:Mice; D018613:Microscopy, Confocal; D010750:Phosphoproteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000235:genetics; D011972:Receptor, Insulin / Q000502:physiology*
D015703:Antigens, CD; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; C526295:Irs1 protein, mouse; D010750:Phosphoproteins; D007335:Insulin-Like Growth Factor II; C435941:INSR protein, human; D017526:Receptor, IGF Type 1; D011972:Receptor, Insulin