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Insulin rapidly induces nuclear translocation of PI3‐Kinase in HepG2 cells
Author(s) -
Kim SungJin
Publication year - 1998
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549800203692
Subject(s) - chromosomal translocation , microbiology and biotechnology , kinase , chemistry , biology , biochemistry , gene
Insulin action on nuclear PI3‐Kinase and IRS‐1 was explored in HepG2 cells. Following insulin treatment, the cells were subjected to subcellular fractionation. Western blot analyses were carried out to identify IRS‐1 and PI3‐Kinase in the nuclear and postnuclear preparations. IRS‐1 protein was identified in the nucleus under basal condition. Insulin had no effect in the content of nuclear IRS‐1. In contrast, PI3‐Kinase was not detected under basal condition. However, insulin treatment for 1 to 10 min caused significant increase of PI3‐Kinase in the nucleus while it induced corresponding decrease of PI3‐Kinase in cytoplasm. Strikingly, Insulin stimulated the association of IRS‐1 and PI3‐Kinase in the nucleus in a similar kinetics with the nuclear translocation of PI3‐Kinase. These results suggest that insulin induces nuclear tranlocation of PI3‐Kinase and the translocated PI3‐Kinase associates with nuclear IRS‐1. The association of IRS‐1 and PI3‐Kinase in the nucleus in response to insulin may play important roles in nuclear insulin actions.