An Aspergillus nidulans bZIP response pathway hardwired for defensive secondary metabolism operates through aflR.

Autor: Yin WB; Departments of Medical Microbiology and Immunology Plant Pathology Genetics Bacteriology, University of Wisconsin-Madison, WI, USA., Amaike S, Wohlbach DJ, Gasch AP, Chiang YM, Wang CC, Bok JW, Rohlfs M, Keller NP
Jazyk: angličtina
Zdroj: Molecular microbiology [Mol Microbiol] 2012 Mar; Vol. 83 (5), pp. 1024-34. Date of Electronic Publication: 2012 Feb 10.
DOI: 10.1111/j.1365-2958.2012.07986.x
Abstrakt: The eukaryotic bZIP transcription factors are critical players in organismal response to environmental challenges. In fungi, the production of secondary metabolites (SMs) is hypothesized as one of the responses to environmental insults, e.g. attack by fungivorous insects, yet little data to support this hypothesis exists. Here we establish a mechanism of bZIP regulation of SMs through RsmA, a recently discovered YAP-like bZIP protein. RsmA greatly increases SM production by binding to two sites in the Aspergillus nidulans AflR promoter region, a C6 transcription factor known for activating production of the carcinogenic and anti-predation SM, sterigmatocystin. Deletion of aflR in an overexpression rsmA (OE:rsmA) background not only eliminates sterigmatocystin production but also significantly reduces asperthecin synthesis. Furthermore, the fungivore, Folsomia candida, exhibited a distinct preference for feeding on wild type rather than an OE:rsmA strain. RsmA may thus have a critical function in mediating direct chemical resistance against predation. Taken together, these results suggest RsmA represents a bZIP pathway hardwired for defensive SM production.
(© 2012 Blackwell Publishing Ltd.)
Databáze: MEDLINE
Externí odkaz: