Transcription of a nitrate reductase gene isolated from the symbiotic basidiomycete fungus Hebeloma cylindrosporum does not require induction by nitrate
| Autor: | Jargeat, P., Gay, G., Debaud, J. C., Marmeisse, R. |
|---|---|
| Přispěvatelé: | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2000 |
| Předmět: |
0106 biological sciences
Transcription Genetic Sequence analysis [SDV]Life Sciences [q-bio] Genes Fungal Molecular Sequence Data Biology Nitrate reductase 01 natural sciences Nitrate Reductase Gene Expression Regulation Enzymologic 03 medical and health sciences Exon Nitrate Reductases Gene Expression Regulation Fungal Sequence Homology Nucleic Acid Genetics Amino Acid Sequence Cloning Molecular Symbiosis Molecular Biology Gene ComputingMilieux_MISCELLANEOUS 030304 developmental biology Regulator gene Regulation of gene expression 0303 health sciences Base Sequence Sequence Homology Amino Acid Genetic Complementation Test Intron Sequence Analysis DNA Nitrite reductase Biochemistry Agaricales 010606 plant biology & botany |
| Zdroj: | Molecular and General Genetics MGG Molecular and General Genetics MGG, Springer Verlag, 2000, 263 (6), pp.948-956. ⟨10.1007/PL00008695⟩ |
| ISSN: | 0026-8925 1432-1874 |
| Popis: | Ectomycorrhizal fungi contribute to the nitrogen nutrition of their host plants, but no information is available on the molecular control of their nitrogen metabolism. The cloning and pattern of transcriptional regulation of two nitrite reductase genes of the symbiotic basidiomycete Hebeloma cylindrosporum are presented. The genomic copy of one of these genes (nar1) was entirely sequenced; the coding region is interrupted by 12 introns. The nar1 gene, which is transcribed and codes for a putative 908-amino acid polypeptide complemented nitrate reductase-deficient mutants of H. cylindrosporum upon transformation, thus demonstrating that the gene is functional. The second gene (nar2), for which no mRNA transcripts were detected, is considered to be an ancestral, non-functional duplication of nar1. In a 462-nt partial sequence of nar2 two introns were identified at positions identical to those of introns 8 and 9 of nar1, although their respective nucleotide sequences were highly divergent; the exon sequences were much more conserved. In wild-type strains, transcription of nar1 is repressed in the presence of a high concentration of ammonium. High levels of transcription are observed in the presence of either very low nitrogen concentrations or high concentrations of nitrate or organic N sources such as urea, glycine or serine. This indicates that in H. cylindrosporum, in contrast to all nitrophilous organisms studied so far, an exogenous supply of nitrate is not required to induce transcription of a nitrate reductase gene. In contrast, repression by ammonium suggests the existence of a wide-domain regulatory gene, as already characterized in ascomycete species. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink