A maize zinc-finger protein binds the prolamin box in zein gene promoters and interacts with the basic leucine zipper transcriptional activator Opaque2
Year: 1997
Type: article
Abstract: The prolamin box (P-box) is a highly conserved 7-bp sequence element (5'-TGTAAAG-3') found in the promoters of many cereal seed storage protein genes. Nuclear factors from maize endosperm specifically interact with the P-box present in maize prolamin genes (zeins). The presence of the P-box in all zein gene promoters suggests that interactions between endosperm DNA binding proteins and the P-box may play an important role in the coordinate activation of zein gene expression during endosperm development. We have cloned an endosperm-specific maize cDNA, named prolamin-box binding factor (PBF), that encodes a member of the recently described Dof class of plant Cys2-Cys2 zinc-finger DNA binding proteins. When tested in gel shift assays, PBF exhibits the same sequence-specific binding to the P-box as factors present in maize endosperm nuclei. Additionally, PBF interacts in vitro with the basic leucine zipper protein Opaque2, a known transcriptional activator of zein gene expression whose target site lies 20 bp downstream of the P-box in the 22-kDa zein gene promoter. The isolation of the PBF gene provides an essential tool to further investigate the functional role of the highly conserved P-box in regulating cereal storage protein gene expression.
Institution: University of California San Diego
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2147980878
