title: Autoregulation of ZEB2 expression for zearalenone production in Fusarium graminearum.
abstract: Several Fusarium species produce the polyketide mycotoxin zearalenone (ZEA), a causative agent of hyperestrogenic syndrome in animals that is often found in F. graminearum-infected cereals in temperate regions. The ZEA biosynthetic cluster genes PKS4, PKS13, ZEB1 and ZEB2 encode a reducing polyketide synthase, a non-reducing polyketide synthase, an isoamyl alcohol oxidase and a transcription factor respectively. In this study, the production of two isoforms (ZEB2L and ZEB2S) from the ZEB2 gene in F. graminearum via an alternative promoter was characterized. ZEB2L contains a basic leucine zipper (bZIP) DNA-binding domain at the N-terminus, whereas ZEB2S is an N-terminally truncated form of ZEB2L that lacks the bZIP domain. Interestingly, ZEA triggers the induction of both ZEB2L and ZEB2S transcription. ZEB2L and ZEB2S interact with each other to form a heterodimer that regulates ZEA production by reducing the binding affinity of ZEB2L for the ZEB2L gene promoter. Our study provides insight into the autoregulation of ZEB2 expression by alternative promoter usage and a feedback loop during ZEA production; this regulatory mechanism is similar to that observed in higher eukaryotes.
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Ae Ran
authors.initials: AR
authors.lastname: Park
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Hokyoung
authors.initials: H
authors.lastname: Son
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Kyunghun
authors.initials: K
authors.lastname: Min
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Jinseo
authors.initials: J
authors.lastname: Park
authors.affiliation: Jeonnam Nano Bio Research Center, 515-853, Jangseong, Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Goo
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Sangkee
authors.initials: S
authors.lastname: Rhee
authors.affiliation: Department of Biochemistry, Paichai University, 302-735, Daejeon, Korea.
authors.forename: Suhn-Kee
authors.initials: SK
authors.lastname: Chae
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, 151-921, Seoul, Korea.
authors.forename: Yin-Won
authors.initials: YW
authors.lastname: Lee
mesh_terms: D002523:Edible Grain / Q000737:chemistry; D025461:Feedback, Physiological; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005670:Fusarium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006706:Homeostasis; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms; D055503:Protein Multimerization; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D015025:Zearalenone / Q000096:biosynthesis* / Q000494:pharmacology
chemical_list: D005656:Fungal Proteins; D020033:Protein Isoforms; D014157:Transcription Factors; D015025:Zearalenone