Effect of the Deprivation of Amino Acids on Conidia of Neurospora crassa

Espı́n, Guadalupe; Mora, Jaime

doi:10.1099/00221287-104-2-233

Cited by 15 publications

(8 citation statements)

References 15 publications

(5 reference statements)

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“…When deprived of certain amino acids in the presence of ammonium as a nitrogen source, N. crassa accumulates glutamine and arginine (20). Other conditions that restrict the growth of mycelia, for example, the presence of cycloheximide or transition to the stationary phase of growth, also cause glutamine and arginine to accumulate.…”

Section: Growth Restrictionmentioning

confidence: 99%

“…Since the growth conditions of N. crassa in that work (22) were different from ours (101), any comparison is difficult (17). In addition, glutamine must play an important role in the accumulation of arginine into the vacuole for the following reasons: (i) in contrast with the wild-type strain, the glnr mutant accumulated substantial amounts of arginine in the vacuole and glutamine in the cytosol while growing exponentially (29); (ii) when incubated on minimal medium, amino acid-auxotrophic mutants accumulated glutamine and arginine (20,68); (iii) nitrogen starvation, perhaps signaled by glutamine depletion, causes the accumulated arginine to be released from the vacuole (29, 51); and (iv) the accumulated glutamine prevents arginase induction (68). These data have led us to conclude that during unrestricted growth, endogenous glutamine regulates the accumulation of arginine into the vacuole; however, during restricted growth or in the presence of the glnr mutation, glutamine regulates neither its own synthesis nor the accumulation of arginine by the vacuole (20, 29, 50).…”

Section: Growth Restrictionmentioning

confidence: 99%

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Glutamine metabolism and cycling in Neurospora crassa.

Mora¹

1990

Microbiological Reviews

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Section: Growth Restrictionmentioning

confidence: 99%

Section: Growth Restrictionmentioning

confidence: 99%

Glutamine metabolism and cycling in Neurospora crassa.

Mora¹

1990

Microbiological Reviews

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“…However, the steady-state pool was not clearly localized to the cytosol. Later studies (84,96) acknowledged the importance of knowing the intracellular distribution of arginine, but were unable adequately to specify the instantaneous rate of arginine uptake and sequestration. The difference in the conclusions of Vaca and Mora (226) and Facklam and Marzluf (86) about nitrogen control of arginase may be because the first authors used 1 mM arginine, while the latter used 10 mM as inducer.…”

Section: Downloaded Frommentioning

confidence: 99%

Compartmental and regulatory mechanisms in the arginine pathways of Neurospora crassa and Saccharomyces cerevisiae.

Davis¹

1986

Microbiological Reviews

136

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Arginine metabolism has been studied intensively in manly organisms, beginning in earnest with the discovery of the urea cycle in mammals (139). The genetic control of the arginine pathway was the earliest example of the one-gene, one-enzyme relationship in the biochemical genetics of Neiurosporca crassa (206). The elucidation of the pathway in Escherichia coli followed soon thereafter, the term "repression'' having been coined to describe the regulatory behavior of acetylornithinase (229). The discovery of carbamoyl phosphate in 1955 (131) led to many comparative studies of its metabolism (52, 130, 152). A profound knowledge of arginine metabolism in N. crassa and Sacclhiaonvces (ceev'isiae has developed in the last 25 years. The subject justifies a comparative review, because the two organisms solve similar metabolic problems in different ways. It is likely that the fundamental phenomena of compartmentation and regulation in the two organisms can be seen throughout the evolutionary tree, used variously according to the demands of particular lifestyles. The synthesis of arginine in fungi has three main components: the synthesis of ornithine, the synthesis of carbamoyl phosphate, and the conversion of these two compounds to arginine. The catabolic pathway consists of the hydrolysis of arginine to ornithine and urea, the breakdown of urea to ammonia and carbon dioxide, and the conversion of ornithine to glutamate. A theme to be pursued is how the anabolic and catabolic pathways can each proceed to the exclusion of the other, given ornithine as a common intermediate. A related theme is how carbamoyl phosphate and ornithine are confined to the arginine pathway in the face of enzymes that might divert them to other fates. Both of these matters involve the compartmentation of small molecules by intracellular membranes, which in S. (ereiisiae is supplemented by elaborate enzyme regulatory mechanisms. This review describes the enzymology, genetics, and localization of the arginine enzymes of S. cere\eisiae and N. crassa. This is followed by descriptions of vacuolar function, enzyme regulation, and the integration of relevant factors in adaptation to different environments. Metabolic maps (Fig. 1 and 2) and a gene-enzyme directory (Table 1) are given for N. crassa(and S. cerevisiae. Arginine metabolism in these organisms has been reviewed in more limited ways previously (1

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“…We reported that glutamine, arginine, and other amino acids are accumulated when N. crassa is deprived of an amino acid or at the end of exponential growth (6,18). Mutant strains impaired in the assimilation of ammonium (5,8) are unable to use the nitrogen atoms of ammonium or glutamine for arginine synthesis (7).…”

mentioning

confidence: 99%

Omega-amidase pathway in the degradation of glutamine in Neurospora crassa

Calderón¹,

Morett²,

Mora³

1985

J Bacteriol

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Evidence for the participation of the glutamine transaminase-w-amidase pathway in the utilization of glutamine in Neurospora crassa was obtained. Its participation is indicated by (i) the in vitro activities of glutamine transaminase and w-amidase, (ii) the in vivo accumulation of a-ketoglutaramate when an inhibitor of transamidases is present, and (iii) the inhibition by aminooxyacetic acid and 6-diazo-5-oxo-L-norleucine of the ammonium excreted in the presence of glutamine by a mutant strain that lacks glutamate dehydrogenase and glutamate synthase.

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Effect of the Deprivation of Amino Acids on Conidia of Neurospora crassa

Cited by 15 publications

References 15 publications

Glutamine metabolism and cycling in Neurospora crassa.

Glutamine metabolism and cycling in Neurospora crassa.

Compartmental and regulatory mechanisms in the arginine pathways of Neurospora crassa and Saccharomyces cerevisiae.

Omega-amidase pathway in the degradation of glutamine in Neurospora crassa

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