Plasma membrane V-ATPase controls oncogenic RAS-induced macropinocytosis

Abstract

Oncogenic activation of Ras is associated with the acquisition of a unique set of metabolic dependencies that contribute to tumor cell fitness. Mutant Ras cells are endowed with the capability to internalize and degrade extracellular protein via a fluid-phase uptake mechanism termed macropinocytosis 1 . There is a growing appreciation for the role of this Ras-dependent process in the generation of free amino acids that can be used to support tumor cell growth under nutrient limiting conditions 2 . However, little is known about the molecular steps that mediate the induction of macropinocytosis by oncogenic Ras. Here we identify vacuolar ATPase (v-ATPase) as an essential regulator of Ras-induced macropinocytosis. Oncogenic Ras promotes the translocation of v-ATPase from intracellular membranes to the plasma membrane (PM) via a pathway that requires protein kinase A (PKA) activation by a bicarbonate-dependent soluble adenylate cyclase (sAC). PM accumulation of v-ATPase is necessary for the cholesterol-dependent association of Rac1 with the PM, a prerequisite for the stimulation of membrane ruffling and macropinocytosis. These observations identify a link between v-ATPase trafficking and nutrient supply by macropinocytosis that could be exploited to curtail the metabolic adaptation capacity of mutant Ras tumor cells.To identify essential mediators of Ras-driven macropinocytosis, we conducted a full genome siRNA screen using a microscopy-based high-throughput assay in which oncogenic HRas (HRasV12)-dependent induction of macropinocytosis in HeLa cells is measured by uptake Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms

Manipulation of IRE1-dependent MAPK signaling by a Vibrio agonist-antagonist effector pair

“…However, in the case of oncogenic Ras, activation of Rac is dependent on the activity of the V-ATPase along with its relocation to the plasma membrane (40). Importantly, the activation ERK1/2 MAPK signaling by VopQ does not occur through the growth factor inducible Rasmediated pathway, but instead is dependent on the kinase activity of the ER stress sensor and cell-fate executor, IRE1 (Fig.…”

Rac-GEF/Rac Signaling and Metastatic Dissemination in Lung Cancer

“…Rac1 has been consistently involved in the activation of pro-survival pathways in cancer cells, such as NF-κB, thereby counterbalancing the apoptotic responses triggered by chemotherapeutic agents and radiation therapy (Friedland et al, 2007;Han et al, 2013;Wang et al, 2013Wang et al, , 2016Hein et al, 2016). Regarding cellular metabolism, Rac1 has been widely associated with macropinocytosis, a mechanism of endocytic uptake of extracellular fluid that assists in meeting the increased demand of nutrients required for cancer cells to proliferation (Erami et al, 2017;Ramirez et al, 2019). In NSCLC cells, PI3K/Rac1/Pak1-driven macropinocytosis and engulfing of extracellular proteins represents an adaptive metabolic pathway for surviving in states of glucose deprivation (Hodakoski et al, 2019).…”

The Vacuolar H+ ATPase α3 Subunit Negatively Regulates Migration and Invasion of Human Pancreatic Ductal Adenocarcinoma Cells

“…V-type H + -ATPases (V-ATPases) have also been studied in the context of cancer [6,7]. In contrast to NHE1, NBCs and MCTs, V-ATPases predominantly localize to endosomes and lysosomes, the Golgi apparatus, and other intracellular compartments [8][9][10][11][12][13] and are only found in the plasma membrane in specialized cell types and some cancer cells [6,14,15]. V-ATPases play a pivotal role in controlling the luminal pH of endosomes, lysosomes, and the Golgi apparatus [6,7,14,16].…”

“…In contrast to NHE1, NBCs and MCTs, V-ATPases predominantly localize to endosomes and lysosomes, the Golgi apparatus, and other intracellular compartments [8][9][10][11][12][13] and are only found in the plasma membrane in specialized cell types and some cancer cells [6,14,15]. V-ATPases play a pivotal role in controlling the luminal pH of endosomes, lysosomes, and the Golgi apparatus [6,7,14,16]. Through this, as well as through acidification-independent scaffolding functions, they regulate endocytic trafficking, autophagy, macropinocytosis, lysosomal degradation, metabolism, protein glycosylation, and signaling pathways including notch-, Wnt-, and epidermal growth factor receptor (EGFR) signaling [6,7,[14][15][16].…”

“…V-ATPases play a pivotal role in controlling the luminal pH of endosomes, lysosomes, and the Golgi apparatus [6,7,14,16]. Through this, as well as through acidification-independent scaffolding functions, they regulate endocytic trafficking, autophagy, macropinocytosis, lysosomal degradation, metabolism, protein glycosylation, and signaling pathways including notch-, Wnt-, and epidermal growth factor receptor (EGFR) signaling [6,7,[14][15][16]. V-ATPases consist of a peripheral V 1 section responsible for ATP hydrolysis and a membraneintegral V 0 section, responsible for H + translocation.…”