At least four regulatory genes control sulphur metabolite repression in Aspergillus nidulans

Transcriptional regulation of methionine synthase by homocysteine and choline in Aspergillus nidulans

“…The following strains of A. nidulans from our collection which carry standard markers [23] were used: pyroA4,yA2, used as a reference wild-type strain; metH2,pyroA4,yA2; metH10,pyroA4, yA2; metH2,argB2,nicA2,biA1,yA2; mecC13,anA1,biA1; mecA1, pyroA4,yA2; metG55,pyroA4,yA2; adF9,choA1,pabaA2,yA2; pyrG89,pabaA1;sconB2,pyroA4,yA2 [17];metR1,pyroA4yA2 [18]. The conditional metH null mutant ∆metH:pyr4AlcA-metH, pyrG89,pabaA1 was constructed as described by May [24].…”

“…In this fungus, biosynthesis and metabolism of sulphur amino acids comprises a rich combination of metabolic options (see Figure 1, reviewed in [16]). Several sulphur metabolic genes, particularly those involved in sulphate assimilation, are regulated by a cascade of negatively acting scon (sulphur controller) genes [17] and the positively acting metR gene, encoding a sulphur-specific transcription factor [18] forming the cysteine-mediated SMR (sulphur metabolite repression) system. The scon mutations render sulphur metabolism insensitive to SMR, whereas metR mutants are methionine-requiring auxotrophs.…”

Role of O‐acetylhomoserine sulfhydrylase in sulfur amino acid synthesis in various yeasts

“…In Succhuromyces cerevisiae, mutants impaired in OAH SHLase are auxotrophs (Cherest et ul., 1969;Yamagata et ul., 1975), while in Aspergillus niduluns, they are prototrophs with a growth rate identical to that of wild-type strains (Paszewski and Grabski, 1974). In the latter organism this enzyme is physiologically active only if synthesis of cysteine from OAS is blocked (Paszewski and Grabski, 1974) or when 0749-503)3/93/121335-08 $09 00 =(; 1993 by John Wiley & Sons Ltd the sulfur metabolite repression system is impaired (Nadolska-Lutyk et al, 1989;Natorff et al, 1993).…”

Involvement of Sulfur in the Biosynthesis of Essential Metabolites in Pathogenic Fungi of Animals, Particularly Aspergillus spp.: Molecular and Therapeutic Implications

“…In A. nidulans, deletion of scon genes results in excessive accumulation of sulfur-containing amino acids. Notably, exposure to Met had no effect on sulfate assimilation in scon deletion mutants, while in wild-type, Met exposure almost eliminated inorganic sulfur assimilation (Natorff et al, 1993). metR transcription increases in scon deletion mutants, particularly sconB2, indicating interaction between the positive and negative elements of sulfur regulation (Natorff et al, 2003).…”