The Agaricus bisporus pruA gene encodes a cytosolic delta 1-pyrroline-5-carboxylate dehydrogenase which is expressed in fruit bodies but not in gill tissue.
A fortuitously cloned 3'-truncated cDNA encoding the Agaricus bisporus delta 1-pyrroline-5-carboxylate dehydrogenase was used to characterize the complete gene. The gene would encode a cytosolic polypeptide of 546 amino acids, and the basidiomycetous gene was evenly expressed in various parts of the mushroom except for the gills. No expression was detected in compost-grown mycelium. The steady-state mRNA level of the gene in the vegetative phase was determined on simple synthetic media and was two- to threefold higher with ammonium or proline as the sole nitrogen source compared to glutamate as the sole nitrogen source. Moreover, the steady-state mRNA level was not markedly influenced by addition of ammonium phosphate to proline- or glutamate-utilizing cultures. The results suggest that ammonium and the amino acids proline and glutamate are equally preferred nitrogen sources in this organism and are consistent with previous observations of H. M Kalisz, D.A. Wood, and D. Moore (Trans. Br. Mycol. Soc. 88:221-227, 1987) that A. bisporus continues to degrade protein and secrete ammonium even if ammonium and glucose are present in the culture medium.
Schaap
P J
PJ
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agriculturál University, The Netherlands.
Müller
Y
Y
Sonnenberg
A S
AS
van Griensven
L J
LJ
Visser
J
J
D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; D000364:Agaricus / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D000595:Amino Acid Sequence; D001483:Base Sequence; D003600:Cytosol / Q000201:enzymology; D004271:DNA, Fungal / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D005800:Genes, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D004271:DNA, Fungal; D000644:Quaternary Ammonium Compounds; D012331:RNA, Fungal; D012333:RNA, Messenger; D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; D000587:Oxidoreductases Acting on CH-NH Group Donors