An endosperm-specific DOF protein from barley, highly conserved in wheat, binds to and activates transcription from the prolamin box of a native B-hordein promoter in barley endosperm

摘要: A cDNA encoding a DNA-binding protein of the DOF class transcription factors was isolated from barley endosperm library. The deduced amino acid sequence for corresponding is 94% identical through domain to prolamin-box (P-box) binding factor PBF maize. gene (BPBF) maps chromosome 7H, and its expression restricted where it precedes that hordein genes. BPBF expressed in bacteria as GST-fusion binds P-box 5'-TGTAAAG-3' containing oligonucleotide derived promoter region an Hor2 gene. Binding prevented when motif mutated 5'-TGTAgAc-3'. activity, present wheat nuclei, interacted similarly with this synthetic oligonucleotide, abolished by 1,10-phenanthroline. Transient experiments developing endosperms demonstrate transactivates element native direct target site essential transactivation since mutations or both transactivation. Evidence also obtained presence Pbf homologue having similar properties BPBF. These results strongly implicate endosperm-specific important activator suggest evolutionary conservation function among small grain cereals.