Transcriptional Regulation Of Importin13Gene

In eukaryotes,transcription initiation complex components, most of transcription factors and regulation factors and cell-cycle regulatory proteins which are essential for protecting the normal life activities of cell growth and differentiation, need to be get in or out of the nucleus at the right time and space. The nucleocytoplasmic transport mediated by Importin β family proteins is the main nucleocytoplasmic trafficking pathway, so the expression regulation of Importin-β family is also an important way to regulate the nucleocytoplasmic transport. As a member of Importin-β family, Importin13(IPO13) is identified to be a rare bidirectional transport receptor in mammals. Studying the transcriptional regulation of IPO13will has great significance.In order to study IPO13transcriptional regulation,we analyze the expression and distribution of some transcription factors and IPO13in this study.and we predict the possible transcription factor binding sites on IPO13promoter by using widely used JASPAR database and MAPPER database. We construct luciferase report plasmid respectively which contains IPO13(-2000～-+162) and IPO13(-433～+162) fragment,and then we determine that MEF2C can bind to E-BOX element on IPO13promoter with a series of luciferase activity assays. Then, we verify this conclusion again with the ChIP and EMSA assays. The next step,We consider whether MEF2C promote the expression of endogenous IPO13. So we overexpress the MEF2C in293T cells,and the result proves that MEF2C can actually promote IPO13expression.This conclution offer a good model to studying the transcriptional regulation of other members of Importin β family, and a good foundation for understanding how IPO13participates in the cell life events in different cells at different stages.