title: The low affinity glucose transporter HxtB is also involved in glucose signalling and metabolism in Aspergillus nidulans.
abstract: One of the drawbacks during second-generation biofuel production from plant lignocellulosic biomass is the accumulation of glucose, the preferred carbon source of microorganisms, which causes the repression of hydrolytic enzyme secretion by industrially relevant filamentous fungi. Glucose sensing, subsequent transport and cellular signalling pathways have been barely elucidated in these organisms. This study therefore characterized the transcriptional response of the filamentous fungus Aspergillus nidulans to the presence of high and low glucose concentrations under continuous chemostat cultivation with the aim to identify novel factors involved in glucose sensing and signalling. Several transcription factor- and transporter-encoding genes were identified as being differentially regulated, including the previously characterized glucose and xylose transporter HxtB. HxtB was confirmed to be a low affinity glucose transporter, localizing to the plasma membrane under low- and high-glucose conditions. Furthermore, HxtB was shown to be involved in conidiation-related processes and may play a role in downstream glucose signalling. A gene predicted to encode the protein kinase PskA was also identified as being important for glucose metabolism. This study identified several proteins with predicted roles in glucose metabolic processes and provides a foundation for further investigation into the response of biotechnologically important filamentous fungi to glucose.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Thaila Fernanda
authors.initials: TF
authors.lastname: Dos Reis
authors.affiliation: Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355, Berlin, Germany.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Nitsche
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Pollyne Borborema Almeida
authors.initials: PB
authors.lastname: de Lima
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Leandro José
authors.initials: LJ
authors.lastname: de Assis
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Laura
authors.initials: L
authors.lastname: Mellado
authors.affiliation: Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68588-0660, United States of America.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Harris
authors.affiliation: Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355, Berlin, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Meyer
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brazil.
authors.forename: Renato A Corrêa
authors.initials: RA
authors.lastname: Dos Santos
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brazil.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Riaño-Pachón
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Laure Nicolas Annick
authors.initials: LN
authors.lastname: Ries
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo Brazil.
authors.forename: Gustavo H
authors.initials: GH
authors.lastname: Goldman
mesh_terms: D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D050260:Carbohydrate Metabolism / Q000235:genetics; D019295:Computational Biology / Q000379:methods; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D063990:Gene Ontology; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D051246:Glucose Transport Proteins, Facilitative / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D021381:Protein Transport; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic; D018631:ras Proteins / Q000378:metabolism
chemical_list: D051246:Glucose Transport Proteins, Facilitative; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D018631:ras Proteins; D005947:Glucose