title: The loss of the inducible Aspergillus carbonarius MFS transporter MfsA leads to ochratoxin A overproduction.
abstract: Ochratoxin A (OTA), a nephrotoxic compound produced by certain Aspergillus and Penicillium species, is one of the most abundant mycotoxins in food commodities. Aspergillus carbonarius is the main source of OTA in wine, grape juice and dried vine fruits. Although many studies have focused on OTA production by A. carbonarius, little is known about the genes related to OTA production and transport. We have found a transporter that belongs to the major facilitator superfamily (MfsA) which is highly expressed with a 102-fold induction in an ochratoxigenic A. carbonarius strain compared to a low OTA producer strain. The encoding mfsA gene shows similarity to the multidrug efflux transporter flu1 from Candida albicans. A high number of putative transcription factor binding sites involved in the response to stress were identified within the promoter of mfsA. Phenotypical analysis of ΔmfsA deletion mutants revealed that the loss of mfsA leads to a slight growth reduction and increased OTA production. We therefore hypothesize that MfsA could be a stress response transporter whose disruption could cause an increase in oxidative stress together with a stimulation of mycotoxin production.
authors.affiliation: Departamento de Ciencias de los Alimentos, Instituto de Agroquímica y Tecnología de los Alimentos (IATA-CSIC), C/Catedrático Agustín Escardino 7, Paterna, 46980 Valencia, Spain; Departamento de Medicina Preventiva y Salud Pública, Ciencias de la Alimentación, Bromatología, Toxicología y Medicina Legal, Universitat de València, Vicente Andrès Estellès s/n, Burjassot, 46100 Valencia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Crespo-Sempere
authors.affiliation: Departamento de Ciencias de los Alimentos, Instituto de Agroquímica y Tecnología de los Alimentos (IATA-CSIC), C/Catedrático Agustín Escardino 7, Paterna, 46980 Valencia, Spain; Departamento de Medicina Preventiva y Salud Pública, Ciencias de la Alimentación, Bromatología, Toxicología y Medicina Legal, Universitat de València, Vicente Andrès Estellès s/n, Burjassot, 46100 Valencia, Spain.
authors.forename: P V
authors.initials: PV
authors.lastname: Martínez-Culebras
authors.affiliation: Departamento de Ciencias de los Alimentos, Instituto de Agroquímica y Tecnología de los Alimentos (IATA-CSIC), C/Catedrático Agustín Escardino 7, Paterna, 46980 Valencia, Spain. Electronic address: lgonzalez@iata.csic.es.
authors.forename: L
authors.initials: L
authors.lastname: González-Candelas
mesh_terms: D001230:Aspergillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D005638:Fruit / Q000382:microbiology; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics*; D008969:Molecular Sequence Data; D009793:Ochratoxins / Q000096:biosynthesis*; D018384:Oxidative Stress / Q000235:genetics; D011401:Promoter Regions, Genetic; D014920:Wine / Q000382:microbiology
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A
keywords: Aspergillus carbonarius; Grapes; Major facilitator superfamily transporters; Ochratoxin production; Wine; mfsA