Structure and regulation of the maize Bronze2 promoter.
The maize Bronze2 (Bz2) gene encodes a glutathione S-transferase that is required for anthocyanin pigment accumulation. Two classes of regulatory proteins, R and C1, are required for transcriptional activation of Bz2 and several additional structural genes. Functional domains of the Bz2 promoter were identified using Bz2 promoter-driven luciferase reporter genes electroporated into maize protoplasts together with R and C1 expression plasmids. Complete regulation was conferred by 224 nt of the Bz2 promoter. Within this region at least two separable regions are independently capable of conferring regulation by R and C1. Predicted regulatory elements corresponding to two classes of sequence motifs, the Myb-box homologous 'C1-motif', TAACTG/CAGTTA, and the G-box and E-box homologous 'R-motif', CACGTG, were shown to be important for full R and C1 activation of the Bz2 promoter. Expression of reconstructed Bz2 genes with mutated promoters was quantified using RNase protection, and this analysis confirmed results obtained using reporter genes.
Bodeau
J P
JP
Department of Biological Sciences, Stanford University, CA 94305, USA.
Walbot
V
V
D000872:Anthocyanins / Q000096:biosynthesis; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017930:Genes, Reporter / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011523:Protoplasts; D011993:Recombinant Fusion Proteins; D017384:Sequence Deletion; D015533:Transcriptional Activation / Q000235:genetics; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D000872:Anthocyanins; D011993:Recombinant Fusion Proteins; D008156:Luciferases; D005982:Glutathione Transferase