Phosphorylation of histone H3 at Thr3 is part of a combinatorial pattern that marks and configures mitotic chromatin
better3624 添加于 2009-8-18 11:17
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作 者
Markaki Y, Christogianni A, Politou AS, Georgatos SD
摘 要
We have previously shown that histone H3 is transiently phosphorylated at Thr3 during mitosis. Extending these studies, we now report that phosphorylated Thr3 is always in cis to trimethylated Lys4 and dimethylated Arg8, forming a new type of combinatorial modification, which we have termed PMM. PMM-marked chromatin emerges at multiple, peripheral sites of the prophase nucleus, then forms distinct clusters at the centric regions of metaphase chromosomes, and finally spreads (as it wanes) to the distal areas of segregating chromatids. The characteristic prophase pattern can be reproduced by expressing ectopically the kinase haspin at interphase, suggesting that the formation of the PMM signature does not require a pre-existing mitotic environment. On the other hand, the ;dissolution' and displacement of PMM clusters from a centric to distal position can be induced by partial dephosphorylation or chromosome unravelling, indicating that these changes reflect the regulated grouping and scrambling of PMM subdomains during cell division. Formation of PMM is prevented by haspin knockdown and leads to delayed exit from mitosis. However, PMM-negative cells do not exhibit major chromosomal defects, suggesting that the local structures formed by PMM chromatin may serve as a ;licensing system' that allows quick clearance through the metaphase-anaphase checkpoint. -
详细资料
- 文献种类:期刊
- 期刊名称: Journal of Cell Science
- 期刊缩写: J Cell Sci
- 期卷页: 2009年 第122卷 第Pt 16期 2809-2819页
- 地址: Laboratory of Biology, Stem Cell and Chromatin Group, The University of Ioannina School of Medicine and The Biomedical Institute of Ioannina (BRI/FORTH), Dourouti, 45 110 Ioannina, Greece
- ISBN: 0021-9533
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