ANALYSIS OF NUCLEAR PROTEINS INTERACTING WITH A WHEAT ALPHA BETA-GLIADIN SEED STORAGE PROTEIN GENE/

The promoter region ( -524 to -46) of the wheat alpha/beta-gliadin see d storage protein gene was analyzed for interactions with nuclear prot eins from developing wheat seeds. Six complexes were detected within t he first 165 bp upstream of the transcriptional start site. One of the proteins was a non-sequence specific AT-binding protein. The remainin g five proteins bound in a sequence specific manner. One (CABP) mapped to a conserved CA-rich element at -134 to -112 while another (PalBP) mapped to an adjacent, palindromic sequence at -112 to -106. Three pro teins (CTBPs 1-3) formed complexes at two, independent homologous site s. The activities of four of the binding proteins, CTBPs 1-3 and CABP, exhibited similar patterns of expression during seed development: the y first appeared at early to mid stages, reached a maximum at mid stag e and subsequently decreased, paralleling the pattern of gliadin mRNA accumulation. The non-specific AT-binding protein was detected at rela tively high levels only at mid development. PalBP activity, on the oth er hand, first appeared at mid stage and was present at a constant lev el throughout later stages of development. The results suggest that th e binding proteins may regulate gliadin expression in an antagonistic manner.