Simon B, Tillotson L, Brand S J
Massachusetts General Hospital, Department of Medicine, Harvard Medical School, Boston 02114.
FEBS Lett. 1994 Sep 12;351(3):340-4. doi: 10.1016/0014-5793(94)00862-0.
Gastrin transcription in islet cells is activated by a cis-regulatory sequence containing a binding site for the yeast transcription factor RAP1. The DNA-protein interactions between RAP1 protein and the gastrin DNA element determined by methylation interference assays are identical to those of RAP1 and yeast genes. Point mutations in the gastrin RAP1 binding site, which abolished RAP1 binding, decreased transcriptional activation by this sequence. Islet cells revealed a DNA binding protein with RAP1-like binding specificity. These findings support the conclusion that gastrin transcription is activated in mammalian cells by a RAP1-like transcription factor.
胰岛细胞中的胃泌素转录由一个包含酵母转录因子RAP1结合位点的顺式调控序列激活。通过甲基化干扰试验确定的RAP1蛋白与胃泌素DNA元件之间的DNA-蛋白质相互作用与RAP1和酵母基因的相互作用相同。胃泌素RAP1结合位点的点突变消除了RAP1结合，降低了该序列的转录激活作用。胰岛细胞显示出一种具有RAP1样结合特异性的DNA结合蛋白。这些发现支持了这样的结论，即胃泌素转录在哺乳动物细胞中由一种RAP1样转录因子激活。
