Job sharing in the endomembrane system

• Verfasst von: Kriegel, Anne [VerfasserIn]
• Verfasst von: Andrés González, Zaida [VerfasserIn]
• Verfasst von: Medzihradszky, Anna [VerfasserIn]
• Verfasst von: Krüger, Falco [VerfasserIn]
• Verfasst von: Scholl, Stefan [VerfasserIn]
• Verfasst von: Delang, Simon [VerfasserIn]
• Verfasst von: Patir, Meliha Gorkem [VerfasserIn]
• Verfasst von: Pfeiffer, Anne [VerfasserIn]
• Verfasst von: Krebs, Melanie [VerfasserIn]
• Verfasst von: Lohmann, Jan U. [VerfasserIn]
• Verfasst von: Schumacher, Karin [VerfasserIn]
• Titel: Job sharing in the endomembrane system
• Titelzusatz: vacuolar acidification requires the combined activity of V-ATPase and V-PPase
• Verf.angabe: Anne Kriegel, Zaida Andrés, Anna Medzihradszky, Falco Krüger, Stefan Scholl, Simon Delang, M. Görkem Patir-Nebioglu, Gezahegn Gute, Haibing Yang, Angus S. Murphy, Wendy Ann Peer, Anne Pfeiffer, Melanie Krebs, Jan U. Lohmann, Karin Schumacher
• Jahr: 2015
• Umfang: 14 S.
• Fussnoten: Published online January 08, 2016 ; Gesehen am 14.06.2017
• Titel Quelle: Enthalten in: The plant cell
• Ort Quelle: Rockville, Md. : Soc., 1989
• Jahr Quelle: 2015
• Band/Heft Quelle: 27(2015), 12, Seite 3383-3396
• ISSN Quelle: 1532-298X
• DOI: doi:10.1105/tpc.15.00733
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1559748532

Abstract

The presence of a large central vacuole is one of the hallmarks of a prototypical plant cell, and the multiple functions of this compartment require massive fluxes of molecules across its limiting membrane, the tonoplast. Transport is assumed to be energized by the membrane potential and the proton gradient established by the combined activity of two proton pumps, the vacuolar H+-pyrophosphatase (V-PPase) and the vacuolar H+-ATPase (V-ATPase). Exactly how labor is divided between these two enzymes has remained elusive. Here, we provide evidence using gain- and loss-of-function approaches that lack of the V-ATPase cannot be compensated for by increased V-PPase activity. Moreover, we show that increased V-ATPase activity during cold acclimation requires the presence of the V-PPase. Most importantly, we demonstrate that a mutant lacking both of these proton pumps is conditionally viable and retains significant vacuolar acidification, pointing to a so far undetected contribution of the trans-Golgi network/early endosome-localized V-ATPase to vacuolar pH.