Abstract
Neurospora crassa possesses an inducible L-phenylalanine ammonia-lyase that is expressed only when cells are derepressed for nitrogen in the presence of L-phenylalanine. Enzyme synthesis requires both induction by L-phenylalanine and simultaneous nitrogen catabolite derepression. Carbon limitation in the presence of phenylalanine does not elicit induction of L-phenylalanine ammonia-lyase. Specific induction by L-phenylalanine is required, and other amino acids completely failed to induce any lyase activity. The nit-2 gene is a major regulatory locus which is believed to mediate nitrogen catabolite repression in Neurospora. Mutants of nit-2 fail to express any phenylalanine ammonia-lyase activity under conditions of derepression and induction which lead to good enzyme induction in the wild type and in nit-2 revertants. The loss of lyase activity in nit-2 mutants does not result from inducer exclusion, which suggests that the nit-2 gene product has a direct role in controlling the expression of this enzyme. Substantial amounts of the enzyme were detected in the growth medium as well as in cell extracts. Inhibitors of protein synthesis or RNA synthesis block the induction of L-phenylalanine ammonia-lyase, suggesting that expression of this enzyme is controlled at the level of transcription.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Coddington A. Biochemical studies on the nit mutants of Neurospora crassa. Mol Gen Genet. 1976 May 7;145(2):195–206. doi: 10.1007/BF00269594. [DOI] [PubMed] [Google Scholar]
- Facklam T. J., Marzluf G. A. Nitrogen regulation of amino acid catabolism in Neurospora crassa. Biochem Genet. 1978 Apr;16(3-4):343–354. doi: 10.1007/BF00484090. [DOI] [PubMed] [Google Scholar]
- Gross G. G., Bolkart K. H., Zenk M. H. Reduction of cinnamic acid to cinnamaldehyde and alcohol. Biochem Biophys Res Commun. 1968 Jul 26;32(2):173–178. doi: 10.1016/0006-291x(68)90365-3. [DOI] [PubMed] [Google Scholar]
- Gross G. G., Zenk M. H. Reduktion aromatischer Säuren zu Aldehyden und Alkoholen im zellfreien System. 2. Reinigung und Eigenschaften von Aryl-Alkohol: NADP-Oxidoreduktase aus Neurospora crassa. Eur J Biochem. 1969 Apr;8(3):420–425. doi: 10.1111/j.1432-1033.1969.tb00544.x. [DOI] [PubMed] [Google Scholar]
- Grove G., Marzluf G. A. Identification of the product of the major regulatory gene of the nitrogen control circuit of Neurospora crassa as a nuclear DNA-binding protein. J Biol Chem. 1981 Jan 10;256(1):463–470. [PubMed] [Google Scholar]
- Hanson M. A., Marzluf G. A. Control of the synthesis of a single enzyme by multiple regulatory circuits in Neurospora crassa. Proc Natl Acad Sci U S A. 1975 Apr;72(4):1240–1244. doi: 10.1073/pnas.72.4.1240. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOUKOL J., CONN E. E. The metabolism of aromatic compounds in higher plants. IV. Purification and properties of the phenylalanine deaminase of Hordeum vulgare. J Biol Chem. 1961 Oct;236:2692–2698. [PubMed] [Google Scholar]
- Marusich W. C., Jensen R. A., Zamir L. O. Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis. J Bacteriol. 1981 Jun;146(3):1013–1019. doi: 10.1128/jb.146.3.1013-1019.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reinert W. R., Marzluf G. A. Genetic and metabolic control of the purine catabolic enzymes of Neurospora crasse. Mol Gen Genet. 1975 Aug 5;139(1):39–55. doi: 10.1007/BF00267994. [DOI] [PubMed] [Google Scholar]
- Tan S. T., Marzluf G. A. Multiple intracellular peptidases in Neurospora crassa. J Bacteriol. 1979 Mar;137(3):1324–1332. doi: 10.1128/jb.137.3.1324-1332.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang L. W., Marzluf G. A. Nitrogen regulation of uricase synthesis in Neurospora crassa. Mol Gen Genet. 1979 Nov;176(3):385–392. doi: 10.1007/BF00333102. [DOI] [PubMed] [Google Scholar]
- Wolfinbarger L., Jr, Marzluf G. A. Specificity and regulation of peptide transport on Neurospora crassa. Arch Biochem Biophys. 1975 Dec;171(2):637–644. doi: 10.1016/0003-9861(75)90074-0. [DOI] [PubMed] [Google Scholar]
- Zucker M. Induction of Phenylalanine Deaminase by Light and its Relation to Chlorogenic Acid Synthesis in Potato Tuber Tissue. Plant Physiol. 1965 Sep;40(5):779–784. doi: 10.1104/pp.40.5.779. [DOI] [PMC free article] [PubMed] [Google Scholar]