Functional analysis of ABC transporter genes in Aspergillus nidulans.

Maarten A. De Waard , Ciska Braam , Lute-Harm Zwiers , and Alan C. Andrade .

Author address: 

Laboratory of Phytopathology, Wageningen University, The Netherlands. Embrapa Recursos Genéticos e Biotecnologia, Brasilia-DF, Brazi


At present, seven ATP-binding cassette (ABC) transporter genes (atrA-atrG) from Aspergillus nidulans are functionally characterized. Previously, atrB and atrD were identified as multidrug transporter and transporter of antibiotics, respectively. Recently, atrG was characterized as a transporter of azole antifungals. Its physiological function may involve transport of sterols, since sterols induce expression of atrG, reduce efflux of azoles from intact cells, and affect growth of atrG knockout mutants in a temperature-dependent manner. A triple knockout mutant of Aspergillus nidulans of atrB, atrD, and atrG is hypersensitive to a wide range of natural toxic products and drugs and its phenotype is the combination of that of the single knockout mutants. The triple knockout mutant can be useful in screening programs to detect new antifungals. The imaB mutation, previously described in relation to pleiotropic drug resistance, enhances transcription of atrD, atrE, atrF, and atrG, suggesting that imaB may be a regulatory gene of ABC transporter genes. Currently, we try to clone imaB by complementation of imaB mutants with a gene-specific cosmid library

abstract No: 


Full conference title: 

23rd Fungal Genetics Conference
    • Fungal Genetics Conference 23rd (2002)