title: Identification of a novel pathway involving a GATA transcription factor in yeast and possibly in plant Zn uptake and homeostasis.
abstract: To gain a better understanding of the regulation of Zn homeostasis in plants and the degree of conservation of Zn homeostasis between plants and yeast, a cDNA library from the Zn/Cd hyperaccumulating plant species, Noccaea caerulescens, was screened for its ability to restore growth under Zn limiting conditions in the yeast mutant zap1Δ. ZAP1 is a transcription factor that activates the Zn dependent transcription of yeast genes involved in Zn uptake, including ZRT1, the yeast high affinity Zn transporter. From this screen two members of the E2F family of transcription factors were found to activate ZRT1 expression in a Zn independent manner. The activation of ZRT1 by the plant E2F proteins involves E2F-mediated activation of a yeast GATA transcription factor which in turn activates ZRT1 expression. A ZRT1 promoter region necessary for activation by E2F and GATA proteins is upstream of two zinc responsive elements previously shown to bind ZAP1 in ZRT1. This activation may not involve direct binding of E2F to the ZRT1 promoter. The expression of E2F genes in yeast does not replace function of ZAP1; instead it appears to activate a novel GATA regulatory pathway involved in Zn uptake and homeostasis that is not Zn responsive.
authors.affiliation: Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, USA; Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Milner
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Pence
authors.forename: Jiping
authors.initials: J
authors.lastname: Liu
authors.forename: Leon V
authors.initials: LV
authors.lastname: Kochian
mesh_terms: D001692:Biological Transport / Q000187:drug effects / Q000235:genetics; D019607:Brassicaceae / Q000187:drug effects / Q000378:metabolism*; D050684:E2F Transcription Factors / Q000378:metabolism; D050980:GATA Transcription Factors / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005816:Genetic Complementation Test; D006706:Homeostasis / Q000187:drug effects / Q000235:genetics; D007501:Iron / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011401:Promoter Regions, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion / Q000235:genetics; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000187:drug effects; D015032:Zinc / Q000378:metabolism*
chemical_list: D050684:E2F Transcription Factors; D050980:GATA Transcription Factors; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron; D015032:Zinc
keywords: E2F transcription factor; GATA transcription factor; ZRT1; Zn homeostasis