Job Sharing in the Endomembrane System: Vacuolar Acidification Requires the Combined Activity of V-ATPase and V-PPase

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

doi:10.1105/tpc.15.00733

Job Sharing in the Endomembrane System: Vacuolar Acidification Requires the Combined Activity of V-ATPase and V-PPase

Plant Cell. 2015 Dec;27(12):3383-96. doi: 10.1105/tpc.15.00733. Epub 2015 Nov 20.

Authors

Affiliations

¹ Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany.
² Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany.
³ Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742.
⁴ Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907.
⁵ Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 Environmental Science and Technology, University of Maryland, College Park, Maryland 20742.
⁶ Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany [email protected].

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acclimatization
Arabidopsis / cytology
Arabidopsis / enzymology*
Arabidopsis / genetics
Arabidopsis / physiology
Arabidopsis Proteins / antagonists & inhibitors
Arabidopsis Proteins / genetics
Arabidopsis Proteins / metabolism*
Cold Temperature
Endosomes / enzymology
Flowers / cytology
Flowers / enzymology
Flowers / genetics
Flowers / physiology
Genome, Plant / genetics*
Hydrogen-Ion Concentration
Inorganic Pyrophosphatase / antagonists & inhibitors
Inorganic Pyrophosphatase / genetics
Inorganic Pyrophosphatase / metabolism*
Meristem / cytology
Meristem / enzymology
Meristem / genetics
Meristem / physiology
Mutagenesis, Insertional
Phenotype
Plant Roots / cytology
Plant Roots / enzymology
Plant Roots / genetics
Plant Roots / physiology
Seedlings / cytology
Seedlings / enzymology
Seedlings / genetics
Seedlings / physiology
Sequence Analysis, DNA
Vacuolar Proton-Translocating ATPases / antagonists & inhibitors
Vacuolar Proton-Translocating ATPases / genetics
Vacuolar Proton-Translocating ATPases / metabolism*
Vacuoles / enzymology*
trans-Golgi Network / enzymology

Substances

Arabidopsis Proteins
Vacuolar Proton-Translocating ATPases
AVP1 protein, Arabidopsis
Inorganic Pyrophosphatase