Glucose uptake in germinating Aspergillus nidulans conidia: involvement of the creA and sorA genes

• Published in: Microbiology (Society for General Microbiology) Vol. 149; no. 8; pp. 2129 - 2136
• Main Authors: MacCabe, Andrew P, Miro, Pilar, Ventura, Luisa, Ramon, Daniel
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.08.2003; Society for General Microbiology
• Subjects: Aspergillus nidulans; Aspergillus nidulans - drug effects; Aspergillus nidulans - genetics; Aspergillus nidulans - growth & development; Aspergillus nidulans - metabolism; Biological and medical sciences; Biological Transport, Active; creA gene; Drug Resistance, Fungal - genetics; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Genes, Fungal; Glucose - metabolism; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Kinetics; Microbiology; Mutation; Mycology; Repressor Proteins - genetics; sorA gene; sorbose; Sorbose - pharmacology; Fungi; Aspergillus nidulans; Toxicity; Fungi Imperfecti; Glucose; Transport; Uptake; Thallophyta
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.26349-0

1 Instituto de Agroquímica y Tecnología de Alimentos, CSIC, Apartado de Correos 73, Burjassot, 46100 Valencia, Spain 2 Departamento de Medicina Preventiva y Salud Pública, Bromatología, Toxicología y Medicina Legal, Facultad de Farmacia, Universitat de València, Avenida Vicente Andrés Estellés s/n, 46100-Burjassot, Valencia, Spain Correspondence Andrew P. MacCabe andrew{at}iata.csic.es D -Glucose uptake in germinating wild-type Aspergillus nidulans conidia is an energy-requiring process mediated by at least two transport systems of differing affinities for glucose: a low-affinity system ( K m 1·4 mM) and a high-affinity system ( K m 16 µM). The low-affinity system is inducible by glucose; the high-affinity system is subject to glucose repression effected by the carbon catabolite repressor CreA and is absent in sorA3 mutant conidia, which exhibit resistance to L -sorbose toxicity. An intermediate-affinity system ( K m 400 µM) is present in sorA3 conidia germinating in derepressing conditions. creA derepressed mutants show enhanced sensitivity to L -sorbose. The high-affinity uptake system appears to be responsible for the uptake of this toxic sugar. Abbreviations: CCR, carbon catabolite repression; CM, complete medium; GM, germination medium; SGM, supplemented GM