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J Bioenerg Biomembr (2013) 45:477490 DOI 10.1007/s10863-013-9520-1
The basidiomycete Ustilago maydis has two plasma membrane H+-ATPases related to fungi and plants
Leobarda Robles-Martnez & Juan Pablo Pardo & Manuel Miranda &
Tavis L. Mendez & Macario Genaro Matus-Ortega &
Guillermo Mendoza-Hernndez & Guadalupe Guerra-Snchez
Received: 19 April 2013 /Accepted: 20 June 2013 /Published online: 7 July 2013 # Springer Science+Business Media New York 2013
Abstract The fungal and plant plasma membrane H+-ATPases play critical roles in the physiology of yeast, plant and protozoa cells. We identified two genes encoding two plasma membrane H+-ATPases in the basidiomycete Ustilago maydis, one protein with higher identity to fungal (um02581) and the other to plant (um01205) H+-ATPases. Proton pumping activity was 5-fold higher when cells were grown in minimal medium with ethanol compared to cells cultured in rich YPD medium, but total vanadate-sensitive ATPase activity was the same in both conditions. In contrast, the activity in cells cultured in minimal medium with glucose was 2-fold higher than in YPD or ethanol, implicating mechanisms for the regulation of the plasma membrane ATPase activity in U. maydis. Analysis of gene expression of the H+-ATPases from cells grown under different conditions, showed that the transcript expression of um01205 (plant-type) was higher than that of um02581
(fungal-type). The translation of the two proteins was confirmed by mass spectrometry analysis. Unlike bakers yeast and plant H+-ATPases, where the activity is increased by a short incubation with glucose or sucrose, respectively, U. maydis H+-ATPase activity did not change in response to these sugars. Sequence analysis of the two U. maydis H+-ATPases revealed the lack of canonical threonine and serine residues which are targets of protein kinases in Saccharomyces cerevisiae and Arabidopsis thaliana plasma membrane H+-ATPases, suggesting that phosphorylation of the U. maydis enzymes occurs at different amino acid residues.
Keywords Ustilago maydis . Basidiomycete . Proton pump regulation . Plants and fungal PMA . Plasma membrane mass spectrometry . Fungal ATPase
Introduction
The plasma membrane proton ATPase (H+-ATPase) mediates ATP-dependent H+ extrusion from the cell, creating the driving force for nutrients uptake. Plants and fungal cells contain at least one isoform of H+-ATPase that belongs to the P2-type
ATPase family which include the animal Ca2+ and Na+/K+ pumps (Lutsenko and Kaplan 1995). Since this protein...