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. 1980 Jul;143(1):188–197. doi: 10.1128/jb.143.1.188-197.1980

Physiological and regulatory properties of the general amino acid transport system of Neurospora crassa.

R M DeBusk, A G DeBusk
PMCID: PMC294208  PMID: 6447141

Abstract

The fundamental properties of the general amino acid transport system of Neurospora crassa were investigated in the conidial stage of the life cycle. The transport activity was found to be under genetic control, and an isogenic set of mutants deficient for the neutral, basic, or general amino acid transport systems and combinations thereof was constructed and used for analyzing the properties specific to the general permease. Amino acid transport by this system was found to be a carrier-mediated active process with broad specificity for the neutral and basic amino acids. Kinetic analysis revealed that a common binding site functioned to transport both neutral and basic amino acids and that the permease had a high affinity for its substrates. The kinetic parameters Km, Vmax, and Ki were defined for several substrates. Two modes of regulation were detected: substrate inhibition and ammonium repression. Activity of the general system was enhanced by the removal of ammonium ions from the incubation medium with a concomitant decline in either neutral or basic permease activity, suggesting that a common component exists between the neutral and the general systems and between the basic and the general systems.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Benko P. V., Wood T. C., Segel I. H. Multiplicity and regulation of amino acid transport in Penicillium chrysogenum. Arch Biochem Biophys. 1969 Feb;129(2):498–508. doi: 10.1016/0003-9861(69)90207-0. [DOI] [PubMed] [Google Scholar]
  2. DIXON M. The determination of enzyme inhibitor constants. Biochem J. 1953 Aug;55(1):170–171. doi: 10.1042/bj0550170. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. DOWD J. E., RIGGS D. S. A COMPARISON OF ESTIMATES OF MICHAELIS-MENTEN KINETIC CONSTANTS FROM VARIOUS LINEAR TRANSFORMATIONS. J Biol Chem. 1965 Feb;240:863–869. [PubMed] [Google Scholar]
  4. DeBusk B. G., DeBusk A. G. Molecular transport in Neurospora crassa. I. Biochemical properties of a phenylalanine permease. Biochim Biophys Acta. 1965 Jun 15;104(1):139–150. doi: 10.1016/0304-4165(65)90229-1. [DOI] [PubMed] [Google Scholar]
  5. Grenson M., Hou C. Ammonia inhibition of the general amino acid permease and its suppression in NADPH-specific glutamate dehydrogenaseless mutants of saccharomyces cerevisiae. Biochem Biophys Res Commun. 1972 Aug 21;48(4):749–756. doi: 10.1016/0006-291x(72)90670-5. [DOI] [PubMed] [Google Scholar]
  6. Grenson M., Hou C. Ammonia inhibition of the general amino acid permease and its suppression in NADPH-specific glutamate dehydrogenaseless mutants of saccharomyces cerevisiae. Biochem Biophys Res Commun. 1972 Aug 21;48(4):749–756. doi: 10.1016/0006-291x(72)90670-5. [DOI] [PubMed] [Google Scholar]
  7. HOFSTEE B. H. Non-inverted versus inverted plots in enzyme kinetics. Nature. 1959 Oct 24;184:1296–1298. doi: 10.1038/1841296b0. [DOI] [PubMed] [Google Scholar]
  8. Lester G. Genetic control of amino acid permeability in Neurospora crassa. J Bacteriol. 1966 Feb;91(2):677–684. doi: 10.1128/jb.91.2.677-684.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Magill C. W., Nelson S. O., D'Ambrosio S. M., Glover G. I. Histidine uptake in mutant strains of Neurospora crassa via the general transport system for amino acids. J Bacteriol. 1973 Mar;113(3):1320–1325. doi: 10.1128/jb.113.3.1320-1325.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Magill C. W., Sweeney H., Woodward V. W. Histidine uptake in strains of Neurospora crassa with normal and mutant transport systems. J Bacteriol. 1972 Apr;110(1):313–320. doi: 10.1128/jb.110.1.313-320.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Pall M. L. Amino acid transport in Neurospora crassa. I. Properties of two amino acid transport systems. Biochim Biophys Acta. 1969 Jan 28;173(1):113–127. doi: 10.1016/0005-2736(69)90042-x. [DOI] [PubMed] [Google Scholar]
  12. Pall M. L. Amino acid transport in Neurospora crassa. II. Properties of a basic amino acid transport system. Biochim Biophys Acta. 1970 Mar 17;203(1):139–149. doi: 10.1016/0005-2736(70)90044-1. [DOI] [PubMed] [Google Scholar]
  13. Railey R. M., Kinsey J. A. Development of amino acid uptake activity in Neurospora. Can J Microbiol. 1976 Feb;22(2):115–120. doi: 10.1139/m76-017. [DOI] [PubMed] [Google Scholar]
  14. Rao E. Y., Rao T. K., Debusk A. G. Isolation and characterization of a mutant of Neurospora crassa deficient in general amino acid permease activity. Biochim Biophys Acta. 1975 Nov 17;413(1):45–51. doi: 10.1016/0005-2736(75)90057-7. [DOI] [PubMed] [Google Scholar]
  15. Roon R. J., Larimore F., Levy J. S. Inhibition of amino acid transport by ammonium ion in Saccharomyces cerevisiae. J Bacteriol. 1975 Oct;124(1):325–331. doi: 10.1128/jb.124.1.325-331.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Rytka J. Positive selection of general amino acid permease mutants in Saccharomyces cerevisiae. J Bacteriol. 1975 Feb;121(2):562–570. doi: 10.1128/jb.121.2.562-570.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Sanchez S., Martinez L., Mora J. Interactions between amino acid transport systems in Neurospora crassa. J Bacteriol. 1972 Oct;112(1):276–284. doi: 10.1128/jb.112.1.276-284.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Sinoara H. Amino acid transport in spores of Aspergillus oryzae. J Biochem. 1974 Sep;76(3):513–522. doi: 10.1093/oxfordjournals.jbchem.a130595. [DOI] [PubMed] [Google Scholar]
  19. Stadler D. R. Genetic control of the uptake of amino acids in Neurospora. Genetics. 1966 Aug;54(2):677–685. doi: 10.1093/genetics/54.2.677. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Thwaites W. M., Pendyala L. Regulation of amino acid assimilation in a strain of Neurospora crassa lacking basic amino acid transport activity. Biochim Biophys Acta. 1969 Dec 30;192(3):455–461. doi: 10.1016/0304-4165(69)90394-8. [DOI] [PubMed] [Google Scholar]
  21. Tisdale J. H., DeBusk A. G. Developmental regulation of amino acid transport in Neurospora crassa. J Bacteriol. 1970 Nov;104(2):689–697. doi: 10.1128/jb.104.2.689-697.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Wolfinbarger L., Jr, Debusk A. G. Molecular transport. I. In vivo studies of transport mutants of Neurospora crassa with altered amino acid competition patterns. Arch Biochem Biophys. 1971 Jun;144(2):503–511. doi: 10.1016/0003-9861(71)90355-9. [DOI] [PubMed] [Google Scholar]
  23. Wolfinbarger L., Jr, Jervis H. H., DeBusk A. G. Active transport of L-aspartic acid in Neurospora crassa. Biochim Biophys Acta. 1971 Oct 12;249(1):63–68. doi: 10.1016/0005-2736(71)90083-6. [DOI] [PubMed] [Google Scholar]

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