McKeon C, Accili D, Chen H, Pham T, Walker G E
Diabetes Branch, National Institute of Diabetes and Kidney and Digestive Diseases, NIH, Bethesda, Maryland 20892, USA.
Biochem Biophys Res Commun. 1997 Nov 26;240(3):701-6. doi: 10.1006/bbrc.1997.7725.
The insulin receptor gene is induced 8 to 10-fold during adipocyte differentiation. Plasmids containing the promoter, exon 1 and a portion of the first intron from either the mouse or human gene are able to modulate the expression of an insulin receptor/CAT gene 3 to 7-fold during differentiation. We have shown that several nuclear proteins from both preadipocyte and adipocyte nuclear extracts bind to two discrete sites within a 278-bp region in the 5' end of the first intron. Sequence comparison between the first intron of the human gene and the mouse gene shows two regions of sequence identity which correspond to the protein binding regions detected by DNase footprinting. One of these sites binds proteins that are enriched in adipocyte nuclear extracts and can be competed by adipose regulatory element, ARE6.
胰岛素受体基因在脂肪细胞分化过程中被诱导表达8至10倍。含有小鼠或人类基因启动子、外显子1和第一内含子一部分的质粒能够在分化过程中将胰岛素受体/CAT基因的表达调节3至7倍。我们已经表明，来自前脂肪细胞核提取物和脂肪细胞核提取物的几种核蛋白与第一内含子5'端278bp区域内的两个离散位点结合。人类基因和小鼠基因第一内含子之间的序列比较显示出两个序列同一性区域，它们对应于通过DNA酶足迹法检测到的蛋白质结合区域。其中一个位点结合在脂肪细胞核提取物中富集的蛋白质，并且可以被脂肪调节元件ARE6竞争。
