Abstract
In fungi and plants, vacuoles function as a storage and sequestration vessel for a wide variety of ions and are responsible for cytosolic ion homeostasis and responses to ionic shock. In the filamentous fungus Aspergillus nidulans, however, little is known about the molecular genetic mechanisms of vacuolar biogenesis and function. In the present study, we analyzed the function of the aslA gene (AN5583) encoding a novel C2H2-type zinc finger transcription factor (TF) in relation to K+ stress resistance, vacuolar morphology, and vacuolar transporters. The mutant lacking aslA showed increased mycelial growth and decreased branching at high K+ concentrations. Deletion of aslA also caused elevated K+ stress-inducible expression of the genes, nhxA (AN2288), vnxA (AN6986), and vcxA (AN0471), encoding putative endosomal and vacuolar cation/H+ exchangers, as well as cpyA and vpsA genes encoding the proteins involved in vacuolar biogenesis. Interestingly, vacuolar fragmentation induced by K+ stress was alleviated by aslA deletion, resulting in persistence of unfragmented vacuoles. In the presence of bafilomycin, an inhibitor of vacuolar H+-ATPase, the mutant phenotype was suppressed in terms of growth rates and vacuolar morphology. These results together suggest that the C2H2-type zinc finger TF AslA attenuates the K+ stress-inducible expression of the genes encoding the ion pumps involved in vacuolar sequestration of K+ ions powered by vacuolar H+-ATPase, as well as the proteins that function in vacuolar biogenesis.
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Arino, J., Ramos, J., and Sychrova, H. 2010. Alkali metal cation transport and homeostasis in yeasts. Microbiol. Mol. Biol. Rev. 74, 95–120.
Baars, T.L., Petri, S., Peters, C., and Mayer, A. 2007. Role of the V-ATPase in regulation of the vacuolar fission-fusion equilibrium. Mol. Biol. Cell 18, 3873–3882.
Balazs, A., Pocsi, I., Hamari, Z., Leiter, E., Emri, T., Miskei, M., Olah, J., Toth, V., Hegedus, N., Prade, R.A., et al. 2010. AtfA bZIP-type transcription factor regulates oxidative and osmotic stress responses in Aspergillus nidulans. Mol. Genet. Genomics 283, 289–303.
Bonangelino, C.J., Nau, J.J., Duex, J.E., Brinkman, M., Wurmser, A.E., Gary, J.D., Emr, S.D., and Weisman, L.S. 2002. Osmotic stress-induced increase of phosphatidylinositol 3,5-bisphosphate requires Vac14p, an activator of the lipid kinase Fab1p. J. Cell Biol. 156, 1015–1028.
Brett, C.L., Tukaye, D.N., Mukherjee, S., and Rao, R. 2005. The yeast endosomal Na+(K+)/H+ exchanger Nhx1 regulates cellular pH to control vesicle trafficking. Mol. Biol. Cell 16, 1396–1405.
Cagnac, O., Aranda-Sicilia, M.N., Leterrier, M., Rodriguez-Rosales, M.P., and Venema, K. 2010. Vacuolar cation/H+ antiporters of Saccharomyces cerevisiae. J. Biol. Chem. 285, 33914–33922.
Cagnac, O., Leterrier, M., Yeager, M., and Blumwald, E. 2007. Identification and characterization of Vnx1p, a novel type of vacuolar monovalent cation/H+ antiporter of Saccharomyces cerevisiae. J. Biol. Chem. 282, 24284–24293.
Cooke, F.T., Dove, S.K., McEwen, R.K., Painter, G., Holmes, A.B., Hall, M.N., Michell, R.H., and Parker, P.J. 1998. The stress-activated phosphatidylinositol 3-phosphate 5-kinase Fab1p is essential for vacuole function in S. cerevisiae. Curr. Biol. 8, 1219–1222.
Cunningham, K.W. and Fink, G.R. 1996. Calcineurin inhibits VCX1-dependent H+/Ca2+ exchange and induces Ca2+ ATPases in Saccharomyces cerevisiae. Mol. Cell. Biol. 16, 2226–2237.
Dove, S.K., McEwen, R.K., Mayes, A., Hughes, D.C., Beggs, J.D., and Michell, R.H. 2002. Vac14 controls PtdIns(3,5)P(2) synthesis and Fab1-dependent protein trafficking to the multivesicular body. Curr. Biol. 12, 885–893.
Efe, J.A., Botelho, R.J., and Emr, S.D. 2005. The Fab1 phosphatidylinositol kinase pathway in the regulation of vacuole morphology. Curr. Opin. Cell Biol. 17, 402–408.
Fillinger, S., Ruijter, G., Tamas, M.J., Visser, J., Thevelein, J.M., and d’Enfert, C. 2001. Molecular and physiological characterization of the NAD-dependent glycerol 3-phosphate dehydrogenase in the filamentous fungus Aspergillus nidulans. Mol. Microbiol. 39, 145–157.
Gary, J.D., Sato, T.K., Stefan, C.J., Bonangelino, C.J., Weisman, L.S., and Emr, S.D. 2002. Regulation of Fab1 phosphatidylinositol 3-phosphate 5-kinase pathway by Vac7 protein and Fig4, a polyphosphoinositide phosphatase family member. Mol. Biol. Cell 13, 1238–1251.
Gary, J.D., Wurmser, A.E., Bonangelino, C.J., Weisman, L.S., and Emr, S.D. 1998. Fab1p is essential for PtdIns(3)P 5-kinase activity and the maintenance of vacuolar size and membrane homeostasis. J. Cell Biol. 143, 65–79.
Hagiwara, D., Asano, Y., Marui, J., Furukawa, K., Kanamaru, K., Kato, M., Abe, K., Kobayashi, T., Yamashino, T., and Mizuno, T. 2007. The SskA and SrrA response regulators are implicated in oxidative stress responses of hyphae and asexual spores in the phosphorelay signaling network of Aspergillus nidulans. Biosci. Biotechnol. Biochem. 71, 1003–1014.
Hagiwara, D., Suzuki, S., Kamei, K., Gonoi, T., and Kawamoto, S. 2014. The role of AtfA and HOG MAPK pathway in stress tolerance in conidia of Aspergillus fumigatus. Fungal Genet. Biol. C73, 138–149.
Hohmann, S. 2002. Osmotic stress signaling and osmoadaptation in yeasts. Microbiol. Mol. Biol. Rev. 66, 300–372.
Hohmann, S., Krantz, M., and Nordlander, B. 2007. Yeast osmoregulation. Methods Enzymol. 428, 29–45.
Lee, J.I., Choi, J.H., Park, B.C., Park, Y.H., Lee, M.Y., Park, H.M., and Maeng, P.J. 2004. Differential expression of the chitin synthase genes of Aspergillus nidulans, chsA, chsB, and chsC, in response to developmental status and environmental factors. Fungal Genet. Biol. 41, 635–646.
Li, S.C. and Kane, P.M. 2009. The yeast lysosome-like vacuole: end-point and crossroads. Biochim. Biophys. Acta 1793, 650–663.
Livak, K.J. and Schmittgen, T.D. 2001. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCt method. Methods 25, 402–408.
Matheos, D.P., Kingsbury, T.J., Ahsan, U.S., and Cunningham, K.W. 1997. Tcn1p/Crz1p, a calcineurin-dependent transcription factor that differentially regulates gene expression in Saccharomyces cerevisiae. Genes Dev. 11, 3445–3458.
Nass, R., Cunningham, K.W., and Rao, R. 1997. Intracellular sequestration of sodium by a novel Na+/H+ exchanger in yeast is enhanced by mutations in the plasma membrane H+-ATPase. Insights into mechanisms of sodium tolerance. J. Biol. Chem. 272, 26145–26152.
Nass, R. and Rao, R. 1999. The yeast endosomal Na+/H+ exchanger, Nhx1, confers osmotolerance following acute hypertonic shock. Microbiology 145 (Pt 11), 3221–3228.
Ohsumi, K., Matsuda, Y., Nakajima, H., and Kitamoto, K. 2001. Cloning and characterization of the cpyA gene encoding intracellular carboxypeptidase from Aspergillus nidulans. Biosci. Biotechnol. Biochem. 65, 1175–1180.
Peters, C., Baars, T.L., Buhler, S., and Mayer, A. 2004. Mutual control of membrane fission and fusion proteins. Cell 119, 667–678.
Qiu, Q.S. 2012. V-ATPase, ScNhx1p and yeast vacuole fusion. J. Genet. Genomics 39, 167–171.
Quintero, F.J., Blatt, M.R., and Pardo, J.M. 2000. Functional conservation between yeast and plant endosomal Na+/H+ antiporters. FEBS Lett. 471, 224–228.
Sambrook, J. and Russell, D.W. 2001. Molecular cloning: A laboratory manual, 3rd (edn.) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, N.Y., USA.
Shoji, J.Y., Arioka, M., and Kitamoto, K. 2006. Vacuolar membrane dynamics in the filamentous fungus Aspergillus oryzae. Eukaryot. Cell 5, 411–421.
Spielvogel, A., Findon, H., Arst, H.N., Araujo-Bazan, L., Hernandez-Ortiz, P., Stahl, U., Meyer, V., and Espeso, E.A. 2008. Two zinc finger transcription factors, CrzA and SltA, are involved in cation homoeostasis and detoxification in Aspergillus nidulans. Biochem. J. 414, 419–429.
Stathopoulos, A.M. and Cyert, M.S. 1997. Calcineurin acts through the CRZ1/TCN1-encoded transcription factor to regulate gene expression in yeast. Genes Dev. 11, 3432–3444.
Tarutani, Y., Ohsumi, K., Arioka, M., Nakajima, H., and Kitamoto, K. 2001. Cloning and characterization of Aspergillus nidulans vpsA gene which is involved in vacuolar biogenesis. Gene 268, 23–30.
Vida, T.A. and Emr, S.D. 1995. A new vital stain for visualizing vacuolar membrane dynamics and endocytosis in yeast. J. Cell Biol. 128, 779–792.
Zieger, M. and Mayer, A. 2012. Yeast vacuoles fragment in an asymmetrical two-phase process with distinct protein requirements. Mol. Biol. Cell 23, 3438–3449.
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Park, D.S., Yu, Y.M., Kim, Y.J. et al. Negative regulation of the vacuole-mediated resistance to K+ stress by a novel C2H2 zinc finger transcription factor encoded by aslA in Aspergillus nidulans . J Microbiol. 53, 100–110 (2015). https://doi.org/10.1007/s12275-015-4701-8
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DOI: https://doi.org/10.1007/s12275-015-4701-8