title: Regulation of ammonium ion assimilation enzymes in Neurospora crassa nit-2 and ms-5 mutant strains.
abstract: In Neurospora crassa the nit-2 and nmr-1 (ms-5) loci represent the major control genes encoding regulatory proteins that allow the coordinated expression of various systems involved with the utilization of a secondary nitrogen source. In this paper we examined the effect of the nit-2 and ms-5 (nmr-1 locus) mutations on the regulation of the ammonium assimilation enzymes, glutamine synthetase and glutamate dehydrogenase, which are regulated by the products of these genes; however, glutamate synthase is not so regulated. Glutamine synthetase and glutamate dehydrogenase levels are also regulated by the amino nitrogen content. We present evidence that the ms-5 and glnr strains, which behave very similarly in their resistance to glutamine repression, are different and map in different loci.
authors.affiliation: Departamento de Ecología Molecular, Centro de Investigación sobre Fijación de Nitrógeno, UNAM Cuernavaca, Mor., México.
authors.forename: J
authors.initials: J
authors.lastname: Calderón
authors.forename: L M
authors.initials: LM
authors.lastname: Martínez
mesh_terms: D000409:Alanine / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D005970:Glutamate Synthase / Q000235:genetics / Q000378:metabolism*; D005974:Glutamate-Ammonia Ligase / Q000235:genetics / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D005973:Glutamine / Q000378:metabolism; D009154:Mutation; D009492:Neurospora crassa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*
chemical_list: D005971:Glutamates; D000644:Quaternary Ammonium Compounds; D005973:Glutamine; D018698:Glutamic Acid; D002244:Carbon; D005970:Glutamate Synthase; D005969:Glutamate Dehydrogenase; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen; D000409:Alanine