CRISPR-Cas systems exploit viral DNA injection to establish and maintain adaptive immunity.
CRISPR-Cas systems exploit viral DNA injection to establish and maintain adaptive immunity.
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DOI：
10.1038/nature21719
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发表时间：
2017-04-06
期刊：
影响因子：
64.8
通讯作者：
Marraffini LA
中科院分区：
文献类型：
--
作者：
Modell JW;Jiang W;Marraffini LA
CRISPR- cas系统通过从这些入侵者中捕获短DNA序列并将其整合到原核宿主的CRISPR位点中，从而提供对病毒和质粒感染的保护。这些序列被称为间隔序列，被转录成短RNA指南，指定入侵者基因组中Cas核酸酶的切割位点。在病毒感染过程中何时获得间隔序列尚不清楚。为了研究这一点，我们在金黄色葡萄球菌噬菌体感染后，在携带II型CRISPR-Cas9系统的金黄色葡萄球菌细胞中进行间隔获取。我们发现新的间隔物在感染后优先从cos位点获得，cos位点是第一次注射到细胞中的无病毒DNA端。对突变噬菌体感染后获得间隔片段的分析表明，大多数间隔片段是在DNA注射期间获得的，而不是在病毒周期中产生自由DNA末端的其他阶段获得的，例如DNA复制或包装。最后，我们发现从早期注射的基因组区域获得的间隔序列，在感染后立即指导Cas9切割病毒DNA，比从晚期注射区域获得的间隔序列提供更好的免疫力。我们的研究结果表明，CRISPR- cas系统利用噬菌体生命周期来产生间隔获取模式，确保CRISPR免疫应答的成功。
CRISPR-Cas systems provide protection against viral and plasmid infection by capturing short DNA sequences from these invaders and integrating them into the CRISPR locus of the prokaryotic host. These sequences, known as spacers, are transcribed into short RNA guides that specify the cleavage site of Cas nucleases in the genome of the invader. When spacer sequences are acquired during viral infection is not known. To investigate this, we followed spacer acquisition in Staphylococcus aureus cells harboring a type II CRISPR-Cas9 system after infection with the staphylococcal bacteriophage ϕ12. We found that new spacers are acquired immediately following infection preferentially from the cos site, the viral free DNA end that is first injected into the cell. Analysis of spacer acquisition after infection with mutant phages demonstrated that most spacers are acquired during DNA injection, but not during other stages of the viral cycle that produce free DNA ends, such as DNA replication or packaging. Finally, we showed that spacers acquired from early-injected genomic regions, which direct Cas9 cleavage of the viral DNA immediately after infection, provide better immunity than spacers acquired from late-injected regions. Our results reveal that CRISPR-Cas systems exploit the phage life cycle to generate a pattern of spacer acquisition that ensures the success of the CRISPR immune response.
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DOI：
10.1126/science.1165771
发表时间：
2008-12-19
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Marraffini LA;Sontheimer EJ
通讯作者：
Sontheimer EJ
影响因子：
64.8
作者：
Goldberg, Gregory W.;Jiang, Wenyan;Bikard, David;Marraffini, Luciano A.
通讯作者：
Marraffini, Luciano A.
影响因子：
64.5
作者：
Jiang W;Samai P;Marraffini LA
通讯作者：
Marraffini LA
影响因子：
46.9
作者：
Bikard, David;Euler, Chad W.;Jiang, Wenyan;Nussenzweig, Philip M.;Goldberg, Gregory W.;Duportet, Xavier;Fischetti, Vincent A.;Marraffini, Luciano A.
通讯作者：
Marraffini, Luciano A.
影响因子：
64.8
作者：
Levy A;Goren MG;Yosef I;Auster O;Manor M;Amitai G;Edgar R;Qimron U;Sorek R
通讯作者：
Sorek R