2-deoxyglucose transiently inhibits yeast AMPK signaling and triggers glucose transporter endocytosis, potentiating the drug toxicity

Abstract

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 is central to 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 activation of protein phosphatase 1 (PP1) and a concomitant inactivation of Snf1/AMPK. 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.

Snf1/AMPK fine-tunes TORC1 signaling in response to glucose starvation

“…Gat1 (Kulkarni et al, 2006), Gln3 (Bertram et al, 2002; Kulkarni et al ., 2006), Mig1 (DeVit and Johnston, 1999; Ostling and Ronne, 1998; Smith et al, 1999; Treitel et al, 1998), Msn4 (Estruch and Carlson, 1993; Petrenko et al, 2013), and Rod1 (Alvaro et al, 2016; Laussel et al, 2022; O’Donnell and Schmidt, 2019; Shinoda and Kikuchi, 2007). In addition, the dataset also pinpoints potential Snf1 target residues in numerous proteins that have an assigned function as Snf1 effectors such as Aly2 and Bul2 (Bowman et al, 2022; O’Donnell and Schmidt, 2019; Ptacek et al, 2005), Glo3 (Arakel et al, 2019), Gpd2 (Lee et al, 2012), and Npr1 (Brito et al, 2019).…”

PIFiA: Self-supervised Approach for Protein Functional Annotation from Single-Cell Imaging Data

“…In addition to the MDR transporters, the CP-1 group contains 14 novel mother-specific proteins, including several other transporter proteins (Atr1, Ftr1, Hxt6, Mep1, Mep3, Qdr2, and Qdr3), proteins with roles in signaling (Gpa2, Mid2, Psr1), and three relatively uncharacterized proteins, including Ybr016w, which is a tail-anchored plasma membrane protein that is orthologous to human CYSTM1 (cysteine rich transmembrane module containing 1), Ina1, an uncharacterized protein whose paralog protein, Fat3, is required for fatty acid uptake 39 , and Crp1, an uncharacterized protein whose paralog protein, Mdg1, appears to modulate pheromone-mediated signaling and cell polarization 40 (Table S2b).…”