Effects of small molecules on chaperone-mediated autophagy
Effects of small molecules on chaperone-mediated autophagy
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DOI：
10.4161/auto.1.3.2000
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发表时间：
2005-10-01
期刊：
影响因子：
13.3
通讯作者：
Dice, J. Fred
中科院分区：
文献类型：
--
作者：
Finn, Patrick E.;Mesires, Nicholas T.;Dice, J. Fred
自噬，包括大自噬(MA)、伴侣介导的自噬(CMA)、噬菌体、异噬和微自噬，是细胞选择内部成分，如蛋白质、分泌囊、细胞器或异物，并将它们运送到溶酶体进行降解的过程。MA和CMA分别在细胞培养中的血清提取条件下和生物体中的短期和长期饥饿条件下被激活。虽然MA和CMA在相似的条件下被激活，但它们受到不同的机制调节。我们使用脉冲/Chase分析，在大多数细胞内蛋白分解是由于CMA的条件下，测试各种化合物对这一过程的影响。我们发现MA的抑制剂如3-甲基腺嘌呤、Wortmannin和LY294002对CMA没有影响。MA的蛋白质降解对微管抑制剂如秋水仙胺和长春花碱敏感，而CMA对蛋白质的降解不敏感。MA的激动剂雷帕霉素对CMA也没有影响。我们证明，和MA一样，CMA也被蛋白质合成抑制剂山奈素和放线菌亚胺抑制。当p38丝裂原活化蛋白激酶被阻断时，CMA也被部分抑制。最后，我们证明了葡萄糖-6-磷酸脱氢酶抑制剂6-氨基烟酰胺和90千道长的热休克蛋白格尔达霉素具有激活CMA的能力。
Autophagy, including macroautophagy (MA), chaperone-mediated autophagy (CMA), crinophagy, pexophagy and microautophogy, are processes by which cells select internal components such as proteins, secretary vesicles, organelles, or foreign bodies, and deliver them to lysosomes for degradation. MA and CMA are activated during conditions of serum withdrawal in cell culture and during short-term and prolonged starvation in organisms, respectively. Although MA and CMA are activated under similar conditions, they are regulated by different mechanisms. We used pulse/chase analysis under conditions in which most intracellular proteolysis is due to CMA to test a variety of compounds for effects on this process. We show that inhibitors of MA such as 3-methyladenine, wortmannin, and LY294002 have no effect on CMA. Protein degradation by MA is sensitive to microtubule inhibitors such as colcemide and vinblastine, but protein degradation by CMA is not. Activators of MA such as rapamycin also have no effect on CMA. We demonstrate that CMA, like MA, is inhibited by protein synthesis inhibitors anisomycin and cycloheximide. CMA is also partially inhibited when the p38 mitogen activated protein kinase is blocked. Finally we demonstrate that the glucose-6-phophate dehydrogenose inhibitor, 6-aminonicotinamide, and heat shock protein of 90 kilodaltons inhibitor, geldanamycin, have the ability to activate CMA.