Screening Of Novel Cargos Of Arabidopsis Nuclear Import Receptor

It is very important that nuclear-cytoplasmic transport proteins maintain the normal cell activities. We have known17Importin-P proteins in Arabidopsis thaliana, which included6nuclear export transport receptors (Exportins) and11nuclear import transport receptors (Importins). There are few reports about Arabidopsis LDD1,which belongs to the Importin-β family. In this study, we used Arabidopsis LDD1as bait to screen Arabidopsis cDNA library in yeast two-hybrid assay. Our results suggest that62proteins that we obtained are novel candidate cargos, including15enzymes,14transcriptional activity factors,11transport-related proteins,8regulatory proteins,7structural proteins and other functional-unknown proteins. We made a further validation in yeast two-hybrid assay which used the above62proteins, and our results show that16candidate cargos can interact with Arabidopsis LDD1, including C10and C30. Subsequently, we conducted a further analysis for C10and C30, and our findings reveal that C10and C30are novel cargos, which contain a nuclear localization signal sequence. We also verified the interaction between Arabidopsis LDD1and truncated CIO and C30in yeast two-hybrid assay. Finally, we get the conclusion that the truncated C10and C30that containing nuclear localization signal sequence interact with Arabidopsis LDD1. Compared the NLSs in the two cargos, we realize that they are basic amino acid-rich sequence. Our study reveal that Arabidopsis LDD1import two novel cargos with nuclear signal sequence. In Arabidopsis thaliana, LDD1could introduce substrate transportation by NLSs, which makes a contribution to further understand the functions of Arabidopsis LDD1.