Replicative stress induces intragenic transcription of the ASE1 gene that negatively regulates Ase1 activity.
Replicative stress induces intragenic transcription of the ASE1 gene that negatively regulates Ase1 activity.
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DOI：
10.1016/j.cub.2014.03.040
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发表时间：
2014-05-19
期刊：
影响因子：
9.2
通讯作者：
Wang, Yanchang
中科院分区：
文献类型：
--
作者：
McKnight, Kelly;Liu, Hong;Wang, Yanchang
基因内转录起始于基因的编码区，从而产生较短的mRNA和蛋白质。虽然基因内转录本广泛表达，但它们在基因功能调控中的作用仍不清楚。在芽殖酵母中，DNA复制应激激活S期检查点，该检查点稳定复制叉并以短纺锤体将细胞停滞在S期。当酵母细胞用羟基脲（HU）处理，以阻止DNA合成和诱导复制应激，我们发现，Ase 1，一个保守的纺锤体中间区蛋白，出现作为两个短的蛋白质亚型，除了全长蛋白。我们进一步证明，短亚型的结果从基因内转录的ASE 1，这取决于S期检查点。阻断产生短的同种型导致不稳定的S-期纺锤体，其特征在于增加的纺锤体动力学和频繁的纺锤体崩溃。因为短的Ase 1亚型定位于在HU处理的细胞中的纺锤体，并且短的Ase 1亚型的过表达损害全长Ase 1的纺锤体中间区定位，所以短的Ase 1亚型的存在可能通过拮抗全长Ase 1来稳定纺锤体。总之，我们的研究结果揭示了基因内转录作为一种独特的机制，下调基因功能，以应对DNA复制应激。
Intragenic transcripts initiate within the coding region of a gene, thereby producing shorter mRNAs and proteins. Although intragenic transcripts are widely expressed, their role in the functional regulation of genes remains largely unknown. In budding yeast, DNA replication stress activates the S-phase checkpoint that stabilizes replication forks and arrests cells in S-phase with a short spindle. When yeast cells were treated with hydroxyurea (HU) to block DNA synthesis and induce replication stress, we found that Ase1, a conserved spindle midzone protein, appeared as two short protein isoforms in addition to the full-length protein. We further demonstrated that the short isoforms result from intragenic transcription of ASE1, which depends on the S-phase checkpoint. Blocking generation of the short isoforms leads to a destabilized S-phase spindle, characterized by increased spindle dynamics and frequent spindle collapse. Because the short Ase1 isoforms localize at the spindle in HU-treated cells and overexpression of the short Ase1 isoforms impairs the spindle midzone localization of full-length Ase1, it is likely that the presence of short Ase1 isoforms stabilizes the spindle by antagonizing full-length Ase1. Together, our results reveal intragenic transcription as a unique mechanism to down-regulate gene functions in response to DNA replication stress.
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影响因子：
16
作者：
Benanti, Jennifer A.;Matyskiela, Mary E.;Toczyski, David P.
通讯作者：
Toczyski, David P.
影响因子：
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影响因子：
64.5
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ZHOU, Z;ELLEDGE, SJ
通讯作者：
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