...
首页> 外文期刊>Molecular and Cellular Biology >MYC Degradation under Low O2 Tension Promotes Survival by Evading Hypoxia-Induced Cell Death
【24h】

MYC Degradation under Low O2 Tension Promotes Survival by Evading Hypoxia-Induced Cell Death

机译:低氧下MYC降解通过避免缺氧诱导的细胞死亡促进存活

获取原文
           

摘要

Cells encounter oxygen deprivation (hypoxia) in various physiological and pathological contexts. Adaptation to hypoxic stress occurs in part by suppressing MYC, a key regulator of cellular metabolism, proliferation, and survival. Hypoxia has been reported to inhibit MYC through multiple means, including disruption of MYC transcriptional complexes and decreased MYC protein abundance. Here we identify enhanced proteasomal degradation and cathepsin-mediated proteolysis as important mechanisms for hypoxic MYC inhibition in human colon carcinoma cells. MYC protein levels were similarly reduced in hypoxic primary keratinocytes. Increased MYC turnover at low O2 tension was dependent on the E3 ubiquitin ligases FBXW7 and DDB1, as well as hypoxic induction of cathepsins D and S. Reduced MYC protein levels coincided with hypoxic inhibition of RNA polymerase III-dependent MYC target genes, which MYC regulates independently of its binding partner MAX. Finally, MYC overexpression in hypoxic cells promoted cell cycle progression but also enhanced cell death via increased expression of the proapoptotic genes NOXA and PUMA. Collectively, these results indicate that hypoxic cells promote MYC degradation as an adaptive strategy to reduce proliferation, suppress biosynthetic processes, and promote cell survival under low O2 tension.
机译:细胞在各种生理和病理情况下都会遇到缺氧(缺氧)。适应低氧应激的部分原因是抑制了MYC,MYC是细胞代谢,增殖和存活的关键调节剂。缺氧据报道可通过多种途径抑制MYC,包括破坏MYC转录复合物和降低MYC蛋白丰度。在这里,我们确定增强的蛋白酶体降解和组织蛋白酶介导的蛋白水解作用是人类结肠癌细胞中低氧MYC抑制的重要机制。低氧原代角质形成细胞中的MYC蛋白水平同样降低。低O 2 张力下MYC周转率的增加取决于E3泛素连接酶FBXW7和DDB1以及组织蛋白酶D和S的低氧诱导。MYC蛋白水平降低与低氧抑制RNA聚合酶III-依赖的MYC靶基因,MYC不受其结合伴侣MAX的调控。最后,缺氧细胞中MYC的过表达促进细胞周期进程,但通过增加促凋亡基因 NOXA PUMA 的表达来增加细胞死亡。总体而言,这些结果表明低氧细胞促进MYC降解是一种在低O 2 张力下降低增殖,抑制生物合成过程并促进细胞存活的适应性策略。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号