Insulin regulation of glucokinase gene expression: Evidence against a role for sterol regulatory element binding protein 1 in primary hepatocytes
- 20 December 2005
- journal article
- Published by Wiley in FEBS Letters
- Vol. 580 (2) , 410-414
- https://doi.org/10.1016/j.febslet.2005.12.032
Abstract
Liver key genes for carbohydrate and lipid homeostasis are regulated by insulin and glucose. The sterol regulatory-element binding protein-1c (SREBP-1c) has emerged as a mediator of insulin effects on gene transcription, particularly on glucokinase (GK). In this paper, we show that despite stimulation of GK promoter transcription by overexpression of mature SREBP-1c, insulin induced GK transcription at least 4h ahead of accumulation of mature SREBP-1c in the nucleus. Importantly, the knockdown of SREBP-1 mRNA using a RNA-interference technique reduced the level of nuclear SREBP-1 protein, diminished fatty acid synthase mRNA level, but did not affect GK and L-pyruvate kinase mRNA levels. We concluded that SREBP-1 is unlikely to be the mediator of the early insulin effect on GK gene transcription.Keywords
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