The cell wall stress response in Aspergillus niger involves increased expression of the glutamine : fructose-6-phosphate amidotransferase-encoding gene (gfaA) and increased deposition of chitin in the cell wall

• Published in: Microbiology (Society for General Microbiology) Vol. 150; no. 10; pp. 3315 - 3326
• Main Authors: Ram, Arthur F. J, Arentshorst, Mark, Damveld, Robbert A, vanKuyk, Patricia A, Klis, Frans M, van den Hondel, Cees A. M. J. J
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.10.2004
• Subjects: Amino Acid Sequence; Aspergillus niger - enzymology; Aspergillus niger - growth & development; Aspergillus niger - metabolism; Cell Wall - metabolism; Chitin - biosynthesis; Chitin - chemistry; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Fungal; Glucosamine - pharmacology; Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) - genetics; Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) - metabolism; Molecular Sequence Data; Phylogeny
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.27249-0

1 Institute of Biology, Leiden University, Clusius Laboratory, Fungal Genetics Research Group, Wassenaarseweg 64, 2333 AL, Leiden, The Netherlands 2 TNO-Nutrition, Applied Microbiology and Genetechnology, Utrechtseweg 48, 3500 AJ, Zeist, The Netherlands 3 Swammerdam Institute for Life Sciences-Microbiology, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV, Amsterdam, The Netherlands Correspondence Arthur F.J. Ram ram{at}rulbim.leidenuniv.nl Perturbation of cell wall synthesis in Saccharomyces cerevisiae , either by mutations in cell wall synthesis-related genes or by adding compounds that interfere with normal cell wall assembly, triggers a compensatory response to ensure cell wall integrity. This response includes an increase in chitin levels in the cell wall. Here it is shown that Aspergillus niger also responds to cell wall stress by increasing chitin levels. The increased chitin level in the cell wall was accompanied by increased transcription of gfaA , encoding the glutamine : fructose-6-phosphate amidotransferase enzyme, which is responsible for the first and a rate-limiting step in chitin synthesis. Cloning and disruption of the gfaA gene in A. niger showed that it was an essential gene, but that addition of glucosamine to the growth medium could rescue the deletion strain. When the plant-pathogenic fungus Fusarium oxysporum and food spoilage fungus Penicillium chrysogenum were subjected to cell wall stress, the transcript level of their gfa gene increased as well. These observations suggest that cell wall stress in fungi may generally lead to activation of the chitin biosynthetic pathway. Abbreviations: CFW, Calcofluor White; CM, complete medium; MM, minimal medium The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this paper are AY594332 (AbGfaA), AY594333 (FoGfaA) and AY594334 (PcGfaA). Nucleotide sequence data reported are available in the Third Party Annotation Section (TPA) of the GenBank/EMBL/DDBJ database under accession numbers BK005223 (AnGfaA) and BK005224 (GzGfaA).