Abstract
Arabidopsis bZIP transcription factor AtbZIP10 involved in programmed cell death (PCD) specifically interacts with microtubule plus-end tracking protein AtEB1a and AtEB1b. If AtEB1 regulates AtbZIP10's nucleocytoplasmic shuttling, AtEB1s would have an important function to induce PCD. Here, we investigated function of AtEB1 on PCD inducing mechanism as well as details of protein-protein interaction. Co-expression of AtEB1 slightly enhanced signal derived from AtbZIP10-GFP, which was transiently expressed in Arabidopsis mesophyll protoplasts, in cytoplasm. In addition, this enhanced signal of AtbZIP10-GFP in cytoplasm was dramatically amplified by treatment of microtubule depolymerizing agent Taxol. These results suggested specific interaction between AtEB1a,b and AtbZIP10 at plus-end of microtubule participates in AtbZIP10's nucleocytoplasmic shuttling. Since Fumonisin B1 induced higher PCD level in AtEB1a overexpressor, AtEB1's function may be involved in PCD inducing mechanism.
