Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1980 Dec;144(3):983–990. doi: 10.1128/jb.144.3.983-990.1980

Regulation and glutamic acid decarboxylase during Neurospora crassa conidial germination.

R L Christensen, J C Schmit
PMCID: PMC294761  PMID: 6449504

Abstract

Glutamic acid decarboxylase (GAD) from Neurospora crassa was assayed in dormant and germinating conidia that had been permeabilized by toluene and methanol. N. crassa conidia contained 10 times the GAD activity found in vegetativemycelia. During conidial germination, GAD activity rapidly decreased to low levels before germ tubes appeared. GAD activity in germinating conidia closely followed the decreasing rate of glutamic acid metabolism. Inhibiting protein synthesis partially blocked the decrease in GAD activity, but eliminating exogenous carbon sources did not alter the initial rate of decrease in this enzyme. However, when conidia were incubated for more than 3 h in distilled water, GAD activity began to increase and eventually reached levels comparable to those in dormant conidia. Either GAD was reversibly inactivated or this enzyme could be synthesized from endogenous storage compounds when conidia were incubated in distilled water. These results are consistent with the hypothesis that GAD is a developmentally regulated enzyme that is responsible for catalyzing the first step in the metabolism of the large pool of free glutamic acid during conidial germination.

Full text

PDF
983

Selected References

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

  1. Basabe J. R., Lee C. A., Weiss R. L. Enzyme assays using permeabilized cells of Neurospora. Anal Biochem. 1979 Jan 15;92(2):356–360. doi: 10.1016/0003-2697(79)90670-5. [DOI] [PubMed] [Google Scholar]
  2. Beever R. E., Redgwell R. J., Dempsey G. P. Purification and chemical characterization of the rodlet layer of Neurospora crassa conidia. J Bacteriol. 1979 Dec;140(3):1063–1070. doi: 10.1128/jb.140.3.1063-1070.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bhagwat A. S., Mahadevan P. R. Conserved mRNA from the conidia of Neurospora crassa. Mol Gen Genet. 1970;109(2):142–151. doi: 10.1007/BF00269650. [DOI] [PubMed] [Google Scholar]
  4. Combépine G., Turian G. Activités de quelques enzymes associés à la conidiogenèse du Neurospora crassa. Arch Mikrobiol. 1970;72(1):36–47. [PubMed] [Google Scholar]
  5. Dempsey G. P., Beever R. E. Electron microscopy of the rodlet layer of Neurospora crassa conidia. J Bacteriol. 1979 Dec;140(3):1050–1062. doi: 10.1128/jb.140.3.1050-1062.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Fahey R. C., Mikolajczyk S. D., Brody S. Correlation of enzymatic activity and thermal resistance with hydration state in ungerminated Neurospora conidia. J Bacteriol. 1978 Sep;135(3):868–875. doi: 10.1128/jb.135.3.868-875.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Foerster H. F. -aminobutyric acid as a required germinant for mutant spores of Bacillus megaterium. J Bacteriol. 1971 Nov;108(2):817–823. doi: 10.1128/jb.108.2.817-823.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Foerster H. F. Spore pool glutamic acid as a metabolite in germination. J Bacteriol. 1972 Aug;111(2):437–442. doi: 10.1128/jb.111.2.437-442.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hanks D. L., Sussman A. S. The relation between growth, conidiation and trehalase activity in Neurospora crassa. Am J Bot. 1969 Nov-Dec;56(10):1152–1159. [PubMed] [Google Scholar]
  10. Loo M. Some required events in conidial germination of Neurospora crassa. Dev Biol. 1976 Dec;54(2):201–213. doi: 10.1016/0012-1606(76)90299-2. [DOI] [PubMed] [Google Scholar]
  11. Mazón M. J. Effect of glucose starvation on the nicotinamide adenine dinucleotide phosphate-dependent glutamate dehydrogenase of yeast. J Bacteriol. 1978 Feb;133(2):780–785. doi: 10.1128/jb.133.2.780-785.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Mirkes P. E. Polysomes, ribonucleic acid, and protein synthesis during germination of Neurospora crassa conidia. J Bacteriol. 1974 Jan;117(1):196–202. doi: 10.1128/jb.117.1.196-202.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Nelson R. E., Selitrennikoff C. P., Siegel R. W. Developmental regulation of nicotinamide adenine dinucleotide (phosphate) glycohydrolase in Neurospora crassa. Dev Biol. 1976 May;50(1):122–133. doi: 10.1016/0012-1606(76)90072-5. [DOI] [PubMed] [Google Scholar]
  14. Schmit J. C., Brody S. Neurospora crassa conidial germination: role of endogenous amino acid pools. J Bacteriol. 1975 Oct;124(1):232–242. doi: 10.1128/jb.124.1.232-242.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Schmit J. C., Edson C. M., Brody S. Changes in glucosamine and galactosamine levels during conidial germination in Neurospora crassa. J Bacteriol. 1975 Jun;122(3):1062–1070. doi: 10.1128/jb.122.3.1062-1070.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Tuveson R. W., West D. J., Barratt R. W. Glutamic acid dehydrogenases in quiescent and germinating conidia of Neurospora crassa. J Gen Microbiol. 1967 Aug;48(2):235–248. doi: 10.1099/00221287-48-2-235. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES