Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France.
PLoS Genet. 2022 Aug 11;18(8):e1010169. doi: 10.1371/journal.pgen.1010169. eCollection 2022 Aug.
2-deoxyglucose is a glucose analog that impacts many aspects of cellular physiology. After its uptake and its phosphorylation into 2-deoxyglucose-6-phosphate (2DG6P), it interferes with several metabolic pathways including glycolysis and protein N-glycosylation. Despite this systemic effect, resistance can arise through strategies that are only partially understood. In yeast, 2DG resistance is often associated with mutations causing increased activity of the yeast 5'-AMP activated protein kinase (AMPK), Snf1. Here we focus on the contribution of a Snf1 substrate in 2DG resistance, namely the alpha-arrestin Rod1 involved in nutrient transporter endocytosis. We report that 2DG triggers the endocytosis of many plasma membrane proteins, mostly in a Rod1-dependent manner. Rod1 participates in 2DG-induced endocytosis because 2DG, following its phosphorylation by hexokinase Hxk2, triggers changes in Rod1 post-translational modifications and promotes its function in endocytosis. Mechanistically, this is explained by a transient, 2DG-induced inactivation of Snf1/AMPK by protein phosphatase 1 (PP1). We show that 2DG-induced endocytosis is detrimental to cells, and the lack of Rod1 counteracts this process by stabilizing glucose transporters at the plasma membrane. This facilitates glucose uptake, which may help override the metabolic blockade caused by 2DG, and 2DG export-thus terminating the process of 2DG detoxification. Altogether, these results shed a new light on the regulation of AMPK signaling in yeast and highlight a remarkable strategy to bypass 2DG toxicity involving glucose transporter regulation.
2-脱氧葡萄糖是一种葡萄糖类似物,它影响细胞生理的许多方面。在摄取并磷酸化为 2-脱氧葡萄糖-6-磷酸(2DG6P)后,它会干扰包括糖酵解和蛋白质 N-糖基化在内的几种代谢途径。尽管有这种全身性影响,但通过部分了解的策略仍会产生耐药性。在酵母中,2DG 耐药性通常与导致酵母 5'-AMP 激活蛋白激酶(AMPK)、Snf1 活性增加的突变有关。在这里,我们专注于 2DG 耐药性中 Snf1 底物的贡献,即参与营养物质转运体内吞作用的α-抑制素 Rod1。我们报告说,2DG 触发许多质膜蛋白的内吞作用,这主要是通过 Rod1 依赖的方式。Rod1 参与 2DG 诱导的内吞作用,因为 2DG 在被己糖激酶 Hxk2 磷酸化后,触发 Rod1 翻译后修饰的变化,并促进其在内吞作用中的功能。从机制上讲,这是由于短暂的、2DG 诱导的 Snf1/AMPK 失活由蛋白磷酸酶 1(PP1)引起的。我们表明,2DG 诱导的内吞作用对细胞有害,而 Rod1 的缺失通过在质膜上稳定葡萄糖转运体来抵消这一过程。这有助于葡萄糖摄取,这可能有助于克服 2DG 引起的代谢阻断,并促进 2DG 外排-从而终止 2DG 解毒过程。总之,这些结果为酵母中 AMPK 信号转导的调节提供了新的认识,并强调了一种通过调节葡萄糖转运体来绕过 2DG 毒性的显著策略。