The ORF1 Protein of Arabidopsis LINE Is Localized to the Nucleus and Forms Multimer

Abstract

To study function of the ORF1 protein of Arabidopsis LINEs (Long INterspersed Elements), the ATLN39 ORF1 protein fused with GFP was expressed in tobacco BY2 cells and onion skin cells. We found that the fused protein was localized to the nucleus. Further analysis revealed that the nuclear localization signal (NLS) exists in the C-terminal region of ORF1. We also examined protein-protein interactions by the yeast two-hybrid system, and found that ORF1 interacts with ORF1 itself. The mutant ORF1 protein which lacks NLS was fused with GFP, and was expressed in BY2 or onion cells with the intact ORF1 protein. We found that the fusion protein was localized to the nucleus. These results suggest that ORF1 forms multimer and is localized to the nucleus in plant cells.