Molecular and General Genetics MGG

, Volume 203, Issue 2, pp 346–353 | Cite as

Regulation of gene expression by pH of the growth medium in Aspergillus nidulans

  • Mark X. Caddick
  • Alan G. Brownlee
  • Herbert N. ArstJr.


In the fungus Aspergillus nidulans the levels of a number of enzymes whose location is at least in part extracellular (e.g. acid phosphatase, alkaline phosphatase, phosphodiesterase) and of certain permeases (e.g. that for γ-amino-n-butyrate) are controlled by the pH of the growth medium. For example, at acidic pH, levels of acid phosphatase are high and those of alkaline phosphatase are low whereas at alkaline pH the reverse is true. Mutations in five genes, palA, B, C, E and F, mimic the effects of growth at acid pH whereas mutations in pacC mimic the effects of growth at alkaline pH. palA, B, C, E and F mutations result in an intracellular pH (pHin) which is more alkaline than that of the wild type whereas pacC mutations result in a pHin more acidic than that of the wild type. This indicates that these mutations exert their primary effects on the regulation of gene expression by pH rather than on the pH homeostatic mechanism but that the expression of at least some component(s) of the pH homeostatic mechanism is subject to the pH regulatory system. It is suggested that pacC might be a wide domain regulatory gene whose product acts positively in some cases (e.g. acid phosphatase) and negatively in others (e.g. alkaline phosphatase). The products of palA, B, C, E and F are proposed to be involved in a metabolic pathway leading to synthesis of an effector molecule able to prevent the (positive and negative) action of the pacC product.

These genes are, to our knowledge, the first examples of genes involved in the regulation of extracellular enzyme and permease synthesis by the pH of the growth medium to be described in any organism.

Key words

Aspergillus nidulans Extracellular enzymes Gene regulation Permeases pH regulation 


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  1. Alderson T, Hartley MJ (1969) Specificity for spontaneous and induced forward mutation at several gene loci in Aspergillus nidulans. Mutat Res 8:255–264Google Scholar
  2. Arst HN Jr (1976) Integrator gene in Aspergillus nidulans. Nature 262:231–234Google Scholar
  3. Arst HN Jr, Bailey CR (1977) The regulation of carbon metabolism in Aspergillus nidulans. In: Smith JE, Pateman JA (eds) Genetics and physiology of Aspergillus. Academic Press, London, pp 131–146Google Scholar
  4. Arst HN Jr, Cove DJ (1969) Methylammonium resistance in Aspergillus nidulans. J Bacteriol 98:1284–1293Google Scholar
  5. Arst HN Jr, Cove DJ (1970) Molybdate metabolism in Aspergillus nidulans. II. Mutations affecting phosphatase activity or galactose utilization. Mol Gen Genet 108:146–153Google Scholar
  6. Arst HN Jr, Cove DJ (1973) Nitrogen metabolite repression in Aspergillus nidulans. Mol Gen Genet 126:111–141Google Scholar
  7. Arst HN Jr, Scazzocchio C (1985) Formal genetics and molecular biology of the control of gene expression in Aspergillus nidulans. In: Bennett JW, Lasure LL (eds) Gene manipulations in fungi. Academic Press, New York, pp 309–343Google Scholar
  8. Arst HN Jr, Penfold HA, Bailey CR (1978) Lactam utilisation in Aspergillus nidulans: evidence for a fourth gene under the control of the integrator gene intA. Mol Gen Genet 166:321–327Google Scholar
  9. Arst HN Jr, Bailey CR, Penfold HA (1980) A possible rôle for acid phosphatase in γ-amino-n-butyrate uptake in Aspergillus nidulans. Arch Microbiol 125:153–158Google Scholar
  10. Arst HN Jr, Tollervey DW, Sealy-Lewis HM (1982) A possible regulatory gene for the molybdenum-containing cofactor in Aspergillus nidulans. J Gen Microbiol 128:1083–1093Google Scholar
  11. Bailry CR, Arst HN Jr, Penfold HA (1980) A third gene affecting GABA transminase levels in Aspergillus nidulans. Genet Res 36:167–180Google Scholar
  12. Bailey CR, Penfold HA, Arst HN Jr (1979) Cis-dominant regulatory mutations affecting the expression of GABA permease in Aspergillus nidulans. Mol Gen Genet 169:79–83Google Scholar
  13. Brownlee AG, Arst HN Jr (1983) Nitrate uptake in Aspergillus nidulans and involvement of the third gene of the nitrate assimilation gene cluster. J Bacteriol 155:1138–1146Google Scholar
  14. Brownlee AG, Arst HN Jr (1984) Quench correction of incorporated carbon-14 in Aspergillus nidulans counted on filter discs. J Microbiol Methods 2:83–91Google Scholar
  15. Caddick MX, Arst HN Jr (1986) Structural genes for phosphatases in Aspergillus nidulans. Genet Res 47:83–91Google Scholar
  16. Caddick MX, Brownlee AG, Arst HN Jr (1986) Phosphatase regulation in Aspergillus nidulans: responses to nutritional starvation. Genet Res 47:93–102Google Scholar
  17. Clutterbuck AJ (1984) Loci and linkage map of the filamentous fungus Aspergillus nidulans (Eidam) Winter (n=8). Genetic Maps 3:265–273Google Scholar
  18. Cohen BL (1980) Transport and utilization of proteins by fungi. In: Payne JW (ed) Microorganisms and nitrogen sources. John Wiley & Sons Ltd, London, pp 411–430Google Scholar
  19. Cotton FA, Wilkinson G (1962) Advanced inorganic chemistry. A comprehensive text. Interscience Publishers, New York, pp 784–785Google Scholar
  20. Cove DJ (1966) The induction and repression of nitrate reductase in the fungus Aspergillus nidulans. Biochim Biophys Acta 113:51–56Google Scholar
  21. Cove DJ (1976) Chlorate toxicity in Aspergillus nidulans. Studies of mutants altered in nitrate assimilation. Mol Gen Genet 146:147–159Google Scholar
  22. Dorn G (1965a) Genetic analysis of the phosphatases in Aspergillus nidulans. Genet Res 6:13–26Google Scholar
  23. Dorn G (1965b) Phosphatase mutants in Aspergillus nidulans. Science 150:1183–1184Google Scholar
  24. Gander JE, Janovec S (1984) Regulation of metabolism in Penicillium charlesii by organic acids: role of L-tartaric acid. Curr Top Cell Reg 24:99–109Google Scholar
  25. Harsanyi Z, Dorn GL (1972) Purification and characterization of acid phosphatase V from Aspergillus nidulans. J Bacteriol 110:246–255Google Scholar
  26. Kobayashi H (1985) A proton-translocating ATPase regulates pH of the bacterial cytoplasm. J Biol Chem 260:72–76Google Scholar
  27. Kobayashi H, Suzuki T, Kinoshita N, Unemoto T (1984) Amplification of the Streptococcus faecalis proton-translocating AT-Pase by a decrease in cytoplasmic pH. J Bacteriol 158:1157–1160Google Scholar
  28. Lindberg RA, Rhodes WG, Eirich LD, Drucker H (1982) Extracellular acid proteases from Neurospora crassa. J Bacteriol 150:1103–1108Google Scholar
  29. Nahas E, Terenzi HF, Rossi A (1982) Effect of carbon source and pH on the production and secretion of acid phosphatase (EC and alkaline phosphatase (EC in Neurospora crassa. J Gen Microbiol 128:2017–2021Google Scholar
  30. Wiame J-M, Grenson M, Arst HN Jr (1985) Nitrogen catabolite repression in yeasts and filamentous fungi. Adv Microb Physiol 26:1–88Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Mark X. Caddick
    • 1
  • Alan G. Brownlee
    • 1
  • Herbert N. ArstJr.
    • 1
  1. 1.Department of GeneticsRidley Building, The UniversityNewcastle upon TyneEngland

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