1887

Abstract

Several mutants of isolated as constitutive for arylsulphatase were studied with respect to the regulation of enzymes involved in cysteine and homocysteine synthesis and to the pool of sulphur amino acids. All mutants examined showed a decreased concentration of glutathione as compared with the wild type, and all mutants, with one exception, had a decreased total pool of sulphur amino acids. The results suggest that the mutants are leaky in the sulphate assimilation pathway. They show derepression of cysteine synthase, homocysteine synthase, cystathionine -synthase and -cystathionase. In spite of having derepressed homocysteine synthase, the enzyme which constitutes an alternative pathway for homocysteine synthesis, the mutations do not suppress lesions in genes required for the main homocysteine-synthesizing pathway. This indicates that the derepression of homocysteine synthase is not in itself sufficient for physiological functioning of this enzyme, but seems to depend also on the effectiveness of cysteine synthesis and sulphide formation.

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1984-05-01
2021-10-25
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References

  1. Apte B. N., Bhavsar P. N., Siddiqui O. 1974; The regulation of arylsulphatase in Aspergillus nidulans. Journal of Molecular Biology 86:637–648
    [Google Scholar]
  2. Arst H. N. 1968; Genetic analysis of the first steps of sulphate metabolism in Aspergillus nidulans. Nature, London 219:268–270
    [Google Scholar]
  3. Bessman S. P., Kappanyi Z. H., Wapnir R. A. 1967; A rapid method for homocysteine assay in physiological fluids. Analytical Biochemistry 18:213–219
    [Google Scholar]
  4. Bradford M. M. 1976; A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 72:248–254
    [Google Scholar]
  5. Dobeli H., Nuesch J. 1980; Regulatory properties of O-acetyl-l-serine sulfhydrylase of Cephalosporium acremonium. Evidence of an isoenzyme and its importance in cephalosporin C biosynthesis. Antimicrobial Agents and Chemotherapy 18:111–117
    [Google Scholar]
  6. Guranowski A., Paszewski A. 1982; Metabolism of 5´-methylthioadenosine in Aspergillus nidulans. An alternative pathway for methionine synthesis via utilization of the nucleoside methylthiogroup. Biochimica et biophysica acta 717:289–294
    [Google Scholar]
  7. Kredich N. M., Tomkins G. N. 1966; The enzyme synthesis of l-cysteine in E. coli and S. typhimurium. Journal of Biological Chemistry 241:4955–4965
    [Google Scholar]
  8. Laemmli U. K. 1970; Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, London 227:680–685
    [Google Scholar]
  9. Metzenberg R. L., Parson J. W. 1966; Altered repression of some enzymes of sulphur utilization in a temperature-conditional lethal mutant of Neuro- spora. Proceedings of the National Academy of Sciences of the United States of America 55:629–635
    [Google Scholar]
  10. Morzycka E., Paszewski A. 1982; Cysteine and homocysteine synthesis in Saccharomycopsis lipo- lytica. Identification and characterization of two cysteine synthases. Acta biochimica polonica 29:81–93
    [Google Scholar]
  11. Morzycka E., Sawnor-Korszyńska D., Paszewski A., Grabski J., Raczyńska-Bojanowska K. 1976; Methionine overproduction by Saccharomycopsis lipolytica. Journal of Applied and Environmental Microbiology 32:125–130
    [Google Scholar]
  12. Paszewski A., Grabski J. 1973; Studies on β- cystathionase and O-acetylhomoserine sulfhydrylase as the enzymes of alternative methionine biosynthetic pathways in Aspergillus nidulans. Acta biochimica polonica 20:159–168
    [Google Scholar]
  13. Paszewski A., Grabski J. 1974; Regulation of S- amino acids biosynthesis in Aspergillus nidulans : role of cysteine and/or homocysteine as regulatory effectors. Molecular and General Genetics 132:307–320
    [Google Scholar]
  14. Paszewski A., Grabski J. 1975; Enzymatic lesion in methionine mutants of Aspergillus nidulans: role and regulation of an alternative pathway for cysteine and methionine synthesis. Journal of Bacteriology 124:893–904
    [Google Scholar]
  15. Pieniąźek N. J., Bal J., Balbin E., Stepień P. P. 1974; An Aspergillus nidulans mutant lacking serine transacetylase: evidence for two pathways of cysteine biosynthesis. Molecular and General Genetics 132:363–366
    [Google Scholar]
  16. Pieniąźek N. J., Stipień P. P., Paszewski A. 1973a; An Aspergillus nidulans mutant lacking cystathionine β-synthase: identity of l-serine sulfhydrylase with cystathionine β-synthase and its distinctness from acetyl-L-serine sulfhydrylase. Biochimica et biophysica acta 297:37–47
    [Google Scholar]
  17. Pieniąźek N. J., Kowalska I. M., Stipień P. P. 1973b; Deficiency in methionine adenosyl- transferase resulting in limited repressibility of methionine biosynthetic enzymes in Aspergillus nidulans. Molecular and General Genetics 126:367–374
    [Google Scholar]
  18. Pontecorvo G., Roper J. A., Hemmonds L. M., Mcdonald K. D., Bufton A. W. 1953; The genetics of Aspergillus nidulans. Advances in Genetics 5:141–238
    [Google Scholar]
  19. Razzell W. E. 1963; Phosphodiesterases. Methods in Enzymology 6:236–258
    [Google Scholar]
  20. Siegel L. M. 1965; A direct microdetermination for sulphide. Analytical Biochemistry 11:126–132
    [Google Scholar]
  21. Siddiqui O., Apte B. N., Pitale M. P. 1966; Genetic regulation of aryl-sulphatase in Aspergillus nidulans. Cold Spring Harbor Symposia on Quantitative Biology 31:381–382
    [Google Scholar]
  22. De Vito P. C., Dreyfuss J. 1964; Metabolic regulation of adenosine triphosphate sulphurylase in yeast. Journal of Bacteriology 88:1341–1348
    [Google Scholar]
  23. Wiebers J. L., Garner Y. 1967; Acyl derivatives of homoserine as substrates for homocysteine synthesis in Neurospora crassa, yeast and Escherichia coli. Journal of Biological Chemistry 242:5644–5649
    [Google Scholar]
  24. Yamagata S., Takeshima K. 1975; O- Acetylserine and O-acetylhomoserine sulfhydrylase of yeast: studies with methionine auxotrophs. Journal of Biochemistry 77:1029–1036
    [Google Scholar]
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