Abstract
H+-PPase is the membrane bound proton pump on plant vacuole. We found that the promoter region of Arabidopsis H+-PPase gene (AVP1) contains the cis-acting region responsible for expression in pollen. By yeast one-hybrid screening, we identified two novel molecules that can bind to this region. The amino acid identity between them is 45% and they show limited distribution to plant. They contain a region that may constitute a zinc finger and a following region similar to NAC domain. We have shown that they themselves can migrate into nucleus and activate the expression in yeast. We have identified the binding sequence of them by in vitro analysis. We have further clearly shown that they bind to the DNA by zinc finger motif. However, the following NAC-like domain is also indispensable for DNA binding abilities. These data suggest that these molecules function as transcription factor by a novel protein-DNA interacting mode.
