Abstract
Arabidopsis LSD1 is a negative regulator of programmed cell death (PCD). We have demonstrated that LSD1 is a cytoplasmic retention protein, which inhibits the nuclear transport of nuclear proteins by interacting via its zinc finger motifs in cytoplasm. Because most of characterized LSD1-interacting proteins belong to transcriptional regulators (AtbZIP10, LIN1, IAA8), the function of LSD1 would be involved in transcriptional regulation participating in the promotion of PCD. To clarify the mechanism of physical interaction between LSD1 and these transcriptional regulators, we examined the target recognition sequence of LSD1 by phage display method. As a result, we found that "GxP" motif is a core sequence of target recognition by LSD1. Using yeast two-hybrid system, it was shown that LSD1 interacts with AtbZIP10, LIN1 and IAA8 via this "GxP" motif. The interaction between LSD1 and these proteins in plant cells has been recently investigated by GST-pull-down, co-immunoprecipitation and BiFC methods.
