Molecular characterization of the glnA gene encoding glutamine synthetase from the edible mushroom Agaricus bisporus.
The gene encoding glutamine synthetase (glnA) was isolated from an Agaricus bisporus H39 recombinant lambda phage library. The deduced A. bisporus glutamine synthetase amino acid sequence contains 354 residues. The amino acid sequence is very similar to that derived from the gene coding for glutamine synthetase of the yeast Saccharomyces cerevisiae. The open reading frame is interrupted by four introns. Northern analysis revealed that transcription of the gene is repressed upon addition of ammonium to the culture but the repression was not as strong as that of the gene encoding NADP+ -dependent glutamate dehydrogenase (gdhA). Enzyme activities are low in the presence of ammonium, glutamine and albumin and do not correlate with the mRNA levels revealed by Northern analysis. This suggests that glutamine synthetase expression in A. bisporus is also post-transcriptionally regulated by the nitrogen source.
Kersten
M A
MA
Department of Microbiology and Evolutionary Biology, Faculty of Science, University of Nijmegen, The Netherlands.
Müller
Y
Y
Op den Camp
H J
HJ
Vogels
G D
GD
Van Griensven
L J
LJ
Visser
J
J
Schaap
P J
PJ
D000364:Agaricus / Q000235:genetics* / Q000378:metabolism; D000418:Albumins / Q000494:pharmacology; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D005969:Glutamate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000235:genetics* / Q000378:metabolism; D005973:Glutamine / Q000494:pharmacology; D007438:Introns; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010957:Plasmids; D016133:Polymerase Chain Reaction; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D012331:RNA, Fungal / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D000418:Albumins; D004271:DNA, Fungal; D000644:Quaternary Ammonium Compounds; D012331:RNA, Fungal; D012333:RNA, Messenger; D005973:Glutamine; D005969:Glutamate Dehydrogenase; C081173:glutamine synthetase I; D005974:Glutamate-Ammonia Ligase