TY - JOUR
T1 - Requirement for 3-phosphoinositide-dependent kinase-1 (PDK-1) in insulin-induced glucose uptake in immortalized brown adipocytes
AU - Sakaue, Hiroshi
AU - Nishizawa, Akihiko
AU - Ogawa, Wataru
AU - Teshigawara, Kiyoshi
AU - Mori, Toshiyuki
AU - Takashima, Yasuhiro
AU - Noda, Tetsuo
AU - Kasuga, Masato
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/10/3
Y1 - 2003/10/3
N2 - To provide insight into the physiological importance of 3-phosphoinositide-dependent kinase-1 (PDK-1) in the metabolic actions of insulin, we have generated mice that harbor a PDK-1 gene containing LoxP sites (PDK-1lox/lox mice) and established immortalized brown preadipocyte cell lines both from these animals and from wild-type mice. Exposure to appropriate hormonal inducers resulted in the differentiation of >80% of the immortalized brown preadipocytes derived from both types of mice into mature adipocytes. Introduction of the Cre recombinase with the use of adenovirus-mediated gene transfer induced a dose-dependent decrease in the abundance of PDK-1 in PDK-1lox/lox adipocytes but not in the wild-type cells. In Cre-expressing PDK-1lox/lox adipocytes in which the abundance of PDK-1 was reduced by ∼85%, the insulin-induced phosphorylation both of Akt on threonine 308 and of p70 S6 kinase on threonine-389 was markedly inhibited. The phosphorylation both of Akt on serine 473 and of p42 and p44 isoforms of mitogen-activated protein kinase induced by insulin was not affected by Cre expression, indicating that the latter specifically inhibits PDK-1-dependent signaling. Both glucose uptake and the translocation of glucose transporter 4 to the plasma membrane induced by insulin as well as glucose uptake induced by a constitutively active form of phosphoinositide 3-kinase were also greatly inhibited by Cre expression in PDK1lox/lox adipocytes. Phosphorylation of AMP-activated protein kinase and glucose uptake induced by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) were not affected by Cre expression in PDK-1 lox/lox adipocytes. These results indicate that PDK-1 is essential for insulin-induced glucose uptake in adipocytes.
AB - To provide insight into the physiological importance of 3-phosphoinositide-dependent kinase-1 (PDK-1) in the metabolic actions of insulin, we have generated mice that harbor a PDK-1 gene containing LoxP sites (PDK-1lox/lox mice) and established immortalized brown preadipocyte cell lines both from these animals and from wild-type mice. Exposure to appropriate hormonal inducers resulted in the differentiation of >80% of the immortalized brown preadipocytes derived from both types of mice into mature adipocytes. Introduction of the Cre recombinase with the use of adenovirus-mediated gene transfer induced a dose-dependent decrease in the abundance of PDK-1 in PDK-1lox/lox adipocytes but not in the wild-type cells. In Cre-expressing PDK-1lox/lox adipocytes in which the abundance of PDK-1 was reduced by ∼85%, the insulin-induced phosphorylation both of Akt on threonine 308 and of p70 S6 kinase on threonine-389 was markedly inhibited. The phosphorylation both of Akt on serine 473 and of p42 and p44 isoforms of mitogen-activated protein kinase induced by insulin was not affected by Cre expression, indicating that the latter specifically inhibits PDK-1-dependent signaling. Both glucose uptake and the translocation of glucose transporter 4 to the plasma membrane induced by insulin as well as glucose uptake induced by a constitutively active form of phosphoinositide 3-kinase were also greatly inhibited by Cre expression in PDK1lox/lox adipocytes. Phosphorylation of AMP-activated protein kinase and glucose uptake induced by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) were not affected by Cre expression in PDK-1 lox/lox adipocytes. These results indicate that PDK-1 is essential for insulin-induced glucose uptake in adipocytes.
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U2 - 10.1074/jbc.M306151200
DO - 10.1074/jbc.M306151200
M3 - Article
C2 - 12855688
AN - SCOPUS:0141643192
VL - 278
SP - 38870
EP - 38874
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 40
ER -