Vázquez-Carrada Melissa, Feldbrügge Michael, Olicón-Hernández Dario Rafael, Guerra-Sánchez Guadalupe, Pardo Juan Pablo
Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N Santo Tomás, Ciudad de Mexico C.P. 11340, Mexico.
Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany.
J Fungi (Basel). 2022 May 24;8(6):550. doi: 10.3390/jof8060550.
Plasma membrane H+-ATPases of fungi, yeasts, and plants act as proton pumps to generate an electrochemical gradient, which is essential for secondary transport and intracellular pH maintenance. Saccharomyces cerevisiae has two genes (PMA1 and PMA2) encoding H+-ATPases. In contrast, plants have a larger number of genes for H+-ATPases. In Ustilago maydis, a biotrophic basidiomycete that infects corn and teosinte, the presence of two H+-ATPase-encoding genes has been described, one with high identity to the fungal enzymes (pma1, UMAG_02851), and the other similar to the plant H+-ATPases (pma2, UMAG_01205). Unlike S. cerevisiae, these two genes are expressed jointly in U. maydis sporidia. In the present work, mutants lacking one of these genes (Δpma1 and Δpma2) were used to characterize the role of each one of these enzymes in U. maydis physiology and to obtain some of their kinetic parameters. To approach this goal, classical biochemical assays were performed. The absence of any of these H+-ATPases did not affect the growth or fungal basal metabolism. Membrane potential tests showed that the activity of a single H+-ATPase was enough to maintain the proton-motive force. Our results indicated that in U. maydis, both H+-ATPases work jointly in the generation of the electrochemical proton gradient, which is important for secondary transport of metabolites and regulation of intracellular pH.
真菌、酵母和植物的质膜H⁺-ATP酶作为质子泵发挥作用，以产生电化学梯度，这对于次级转运和细胞内pH维持至关重要。酿酒酵母有两个编码H⁺-ATP酶的基因（PMA1和PMA2）。相比之下，植物拥有更多编码H⁺-ATP酶的基因。在侵染玉米和大刍草的活体营养担子菌玉米黑粉菌中，已描述了两个编码H⁺-ATP酶的基因，一个与真菌酶具有高度同源性（pma1，UMAG_02851），另一个与植物H⁺-ATP酶相似（pma2，UMAG_01205）。与酿酒酵母不同，这两个基因在玉米黑粉菌担孢子中共同表达。在本研究中，利用缺失其中一个基因的突变体（Δpma1和Δpma2）来表征这些酶中的每一种在玉米黑粉菌生理学中的作用，并获得它们的一些动力学参数。为实现这一目标，进行了经典的生化分析。缺失任何一种这些H⁺-ATP酶均不影响生长或真菌基础代谢。膜电位测试表明，单个H⁺-ATP酶的活性足以维持质子动力。我们的结果表明，在玉米黑粉菌中，两种H⁺-ATP酶共同作用产生电化学质子梯度，这对于代谢物的次级转运和细胞内pH调节很重要。
