通过晚期内体酸3,4-双酸抑制mTORC1活动
Andrea L Marat1, Alexander Wallroth1, Wen-Ting Lo1
1Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Roessle-Strasse 10, 13125 Berlin, Germany.
概括
由PI3KC2β产生的酸3,4-双酸[PI(3,4) P2] 作为拉巴胺复合物1 (mTORC1) 途径的新型抑制剂. 这一发现揭示了在营养缺乏期间控制细胞生长的新机制.
科学领域:
- 细胞生物学
- 分子生物学
- 生物化学
背景情况:
- 拉巴胺复合体1 (mTORC1) 的机械标调节细胞生长,并由营养素激活.
- 在血中,I类酸3-激酶 (PI3Ks) 通过酸3,4,5-三酸[PI(3,4,5) P3]的产生刺激mTORC1.
研究的目的:
- 在增长因子剥夺期间抑制mTORC1活动的机制.
- 在溶酶体和晚期内体 (LyLEs) 找出mTORC1信号的新型调节剂.
主要方法:
- 研究了II类PI3Kβ (PI3KC2β) 和其产物酸3,4-双酸盐[PI(3,4) P2]在mTORC1调控中的作用.
- 用于评估mTORC1活性,蛋白与蛋白相互作用和脂质局部化的技术.
主要成果:
- 在LyLEs中由PI3KC2β合成的PI(3,4) P2,作为mTORC1的负调节剂.
- 在缺乏PI3KC2β的细胞中观察到mTORC1的过度激活.
- 证明增长因子剥夺诱导PI3KC2β与mTORC1的猛禽子单元的结合.
- 表明局部PI(3,4) P2合成促进了Raptor与抑制性14-3-3蛋白的结合,抑制了mTORC1.
结论:
- 通过PI3KC2β介导的局部PI(3,4) P2合成是关闭mTORC1的关键机制.
- 在营养或生长因子稀缺的情况下,这种途径为抑制mTORC1信号提供了意想不到的途径.
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