Nuclear importation of Mariner transposases among eukaryotes: motif requirements and homo-protein interactions

• Published in: PloS one 2011-08, Vol.6 (8), p.e23693-e23693
• Main Authors: Demattei, Marie-Véronique, Hedhili, Sabah, Sinzelle, Ludivine, Bressac, Christophe, Casteret, Sophie, Moiré, Nathalie, Cambefort, Jeanne, Thomas, Xavier, Pollet, Nicolas, Gantet, Pascal, Bigot, Yves
• Format: Article
• Language: English
• Subjects: Active Transport, Cell Nucleus; Amino Acid Motifs; Amino Acid Sequence; Analysis; Animal genetics; Animals; Autophagy; Biology; Cell Nucleus - enzymology; Cellular Biology; Collaboration; Computational Biology; Conserved sequence; Cytoplasm; Deoxyribonucleic acid; Dimerization; DNA; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - metabolism; Drosophila; Eukaryotes; Eukaryotic Cells - enzymology; Fluorescence; Genomes; Genomics; Green Fluorescent Proteins - metabolism; HeLa Cells; Host range; Humans; Importation; Isoelectric Point; Life Sciences; Localization; Medicine; Microscopy; Molecular Sequence Data; Molecular Weight; Nuclear Localization Signals - chemistry; Nuclear Localization Signals - metabolism; Nuclei; Overexpression; Plant Cells - metabolism; Point Mutation - genetics; Protein Binding; Protein interaction; Protein Multimerization; Proteins; Recombinant Fusion Proteins - metabolism; Residues; Subcellular Fractions - enzymology; Transcription factors; Transposase; Transposases - chemistry; Transposases - metabolism; Transposons; Trends; Xenopus
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0023693

Mariner-like elements (MLEs) are widespread transposable elements in animal genomes. They have been divided into at least five sub-families with differing host ranges. We investigated whether the ability of transposases encoded by Mos1, Himar1 and Mcmar1 to be actively imported into nuclei varies between host belonging to different eukaryotic taxa. Our findings demonstrate that nuclear importation could restrict the host range of some MLEs in certain eukaryotic lineages, depending on their expression level. We then focused on the nuclear localization signal (NLS) in these proteins, and showed that the first 175 N-terminal residues in the three transposases were required for nuclear importation. We found that two components are involved in the nuclear importation of the Mos1 transposase: an SV40 NLS-like motif (position: aa 168 to 174), and a dimerization sub-domain located within the first 80 residues. Sequence analyses revealed that the dimerization moiety is conserved among MLE transposases, but the Himar1 and Mcmar1 transposases do not contain any conserved NLS motif. This suggests that other NLS-like motifs must intervene in these proteins. Finally, we showed that the over-expression of the Mos1 transposase prevents its nuclear importation in HeLa cells, due to the assembly of transposase aggregates in the cytoplasm.