Biochemistry Department, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038, USA.
Biochem Biophys Res Commun. 2010 Jan 8;391(2):1166-9. doi: 10.1016/j.bbrc.2009.11.115. Epub 2009 Dec 17.
Carbohydrate response element binding protein (ChREBP) is responsible for conversion of dietary carbohydrate to storage fat in liver by coordinating expression of the enzymes that channel glycolytic pyruvate into lipogenesis. The activation of ChREBP in response to high glucose is nuclear localization and transcription, and the inactivation of ChREBP under low glucose involves export from the nucleus to the cytosol. Here we report a new nuclear export signal site ("NES1") of ChREBP. Together these signals provide ChREBP with two NES sequences, both the previously reported NES2 and now the new NES1 coordinate to interact together with CRM1 (exportin) for nuclear export of the carbohydrate response element binding protein.
碳水化合物反应元件结合蛋白（ChREBP）通过协调将糖酵解丙酮酸导入脂肪生成的酶的表达，负责将膳食碳水化合物转化为肝脏中的储存脂肪。高葡萄糖刺激下 ChREBP 的激活涉及核定位和转录，而低葡萄糖下 ChREBP 的失活则涉及从核内输出到细胞质。本文报道了 ChREBP 的一个新的核输出信号位点（“NES1”）。这两个信号共同为 ChREBP 提供了两个 NES 序列，之前报道的 NES2 和现在的新 NES1 一起与 CRM1（exportin）相互作用，以实现碳水化合物反应元件结合蛋白的核输出。
