title: Glutamine metabolism during aerial mycelium growth of Neurospora crassa.
abstract: During vegetative growth, glutamine is accumulated in the mycelium of Neurospora crassa. This high pool of glutamine seems to be required for aerial mycelium growth. Enzymes responsible for the synthesis and catabolism of glutamine were measured before and during the partial transformation of a mycelial mat into aerial mycelium. In the transforming mycelial mat,considerable activities of the biosynthetic NADP-glutamate dehydrogenase and glutamine synthetase (predominantly β polypeptide) and also some activity of glutamate synthase were observed. In the aerial mycelium, glutamine synthetase (predominantly β polypeptide) was detected, but very low activities of NADP-glutamate dehydrogenase and glutamate mycelium could derive from glutamine. No glutaminase activity could be detected. It is suggested that glutamate is formed through the activities of the glutamine transaminase-ω -amidase pathway and another transaminase. High activities of glutamine and alanine transaminases were observed in the aerial mycelium. These results are discussed in terms of the possible role of glutamine as a nitrogen carrier from the mycelium to the growing aerial hyphae.
authors.affiliation: Centro de Inuestigacion sobre Fijacibn de Nitrbgeno, Uniuersidad Nacional Autbnoma de Mixico,Apartado Postal 565-A-Cuernauaca, Mor., Mexico.
authors.forename: M E
authors.initials: ME
authors.lastname: Cárdenas
authors.forename: W
authors.initials: W
authors.lastname: Hansberg
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D003470:Culture Media; D005656:Fungal Proteins / Q000378:metabolism; D018086:Glutamate Dehydrogenase (NADP+) / Q000378:metabolism; D005970:Glutamate Synthase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000737:chemistry / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D005972:Glutaminase / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D025282:Mycelium / Q000254:growth & development* / Q000378:metabolism; D009492:Neurospora crassa / Q000254:growth & development* / Q000378:metabolism*; D000637:Transaminases / Q000378:metabolism
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D005973:Glutamine; D018698:Glutamic Acid; D005970:Glutamate Synthase; D018086:Glutamate Dehydrogenase (NADP+); D000637:Transaminases; C020656:glutamine-pyruvate aminotransferase; D000410:Alanine Transaminase; D005972:Glutaminase; D005974:Glutamate-Ammonia Ligase