Molecular interaction of bZIP domains of GBF1, HY5 and HYH in Arabidopsis seedling development

Abstract

The bZIP proteins, GBF1, HY5 and HYH, play important regulatory roles in Arabidopsis seedling development. Whereas GBF1 plays a dual regulatory role, HY5 and HYH act as positive regulators of photomorphogenesis. The molecular and functional relations of GBF1 with HY5 and HYH in photomorphogenesis have recently been demonstrated. However, the possible interaction of bZIP domain of each of these proteins remains to be investigated. In this study, our results suggest that bZIP domains of HY5 and HYH are able to interact with the bZIP domain of GBF1. Taken together with the earlier study, (9) these results suggest that the N-terminal domain of GBF1 has an inhibitory effect on its interaction with HY5 and HYH.