Nuclear RanGAP Is Required for the Heterochromatin Assembly and Is Reciprocally Regulated by Histone H3 and Clr4 Histone Methyltransferase inSchizosaccharomyces pombe
| Autor: | Kei-ichi Shibahara, Hideo Nishitani, Takeharu Nishimoto, Ayumi Kusano, Jun-ichi Nakayama, Hitoshi Nishijima, Tomoko Yoshioka |
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| Rok vydání: | 2006 |
| Předmět: |
Genetic Markers
Recombinant Fusion Proteins Cell Cycle Proteins Biology Polymerase Chain Reaction Histones Histone H3 Heterochromatin Schizosaccharomyces RanGAP Heterochromatin assembly Molecular Biology DNA Primers Cell Nucleus Base Sequence GTPase-Activating Proteins Articles Histone-Lysine N-Methyltransferase Methyltransferases Cell Biology biology.organism_classification Molecular biology Chromatin Cell biology Kinetics Histone Histone methyltransferase Schizosaccharomyces pombe biology.protein Schizosaccharomyces pombe Proteins Plasmids |
| Zdroj: | Molecular Biology of the Cell. 17:2524-2536 |
| ISSN: | 1939-4586 1059-1524 |
| DOI: | 10.1091/mbc.e05-09-0893 |
| Popis: | Although the Ran GTPase-activating protein RanGAP mainly functions in the cytoplasm, several lines of evidence indicate a nuclear function of RanGAP. We found that Schizosaccharomyces pombe RanGAP, SpRna1, bound the core of histone H3 (H3) and enhanced Clr4-mediated H3-lysine 9 (K9) methylation. This enhancement was not observed for methylation of the H3-tail containing K9 and was independent of SpRna1–RanGAP activity, suggesting that SpRna1 itself enhances Clr4-mediated H3-K9 methylation via H3. Although most SpRna1 is in the cytoplasm, some cofractionated with H3. Sprna1tsmutations caused decreases in Swi6 localization and H3-K9 methylation at all three heterochromatic regions of S. pombe. Thus, nuclear SpRna1 seems to be involved in heterochromatin assembly. All core histones bound SpRna1 and inhibited SpRna1–RanGAP activity. In contrast, Clr4 abolished the inhibitory effect of H3 on the RanGAP activity of SpRna1 but partially affected the other histones. SpRna1 formed a trimeric complex with H3 and Clr4, suggesting that nuclear SpRna1 is reciprocally regulated by histones, especially H3, and Clr4 on the chromatin to function for higher order chromatin assembly. We also found that SpRna1 formed a stable complex with Xpo1/Crm1 plus Ran-GTP, in the presence of H3. |
| Databáze: | OpenAIRE |
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