Human LINE-1 restriction by APOBEC3C is deaminase independent and mediated by an ORF1p interaction that affects LINE reverse transcriptase activity.
Human LINE-1 restriction by APOBEC3C is deaminase independent and mediated by an ORF1p interaction that affects LINE reverse transcriptase activity.
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DOI：
10.1093/nar/gkt898
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发表时间：
2014-01
影响因子：
14.9
通讯作者：
Schumann GG
中科院分区：
文献类型：
--
作者：
Horn AV;Klawitter S;Held U;Berger A;Vasudevan AA;Bock A;Hofmann H;Hanschmann KM;Trösemeier JH;Flory E;Jabulowsky RA;Han JS;Löwer J;Löwer R;Münk C;Schumann GG
LINE-1(L1)反转录转座子是一种可移动的遗传元件，其广泛的增殖导致34%的人类基因组产生∼。它们已被证明是单基因疾病的原因之一。此外，L1编码的内切酶可以引起双链断裂，从而可能导致基因组的不稳定。哺乳动物细胞采取了限制移动性和不受控制的逆转录转位的有害后果的策略。人类APOBEC3蛋白家族的多核苷酸胞苷脱氨酶有助于细胞内防御逆转录因子。APOBEC3成员可抑制35-99%的L1逆转录转座。然而，在L1限制性APOBEC3蛋白存在的情况下发生的基因组L1逆转座子事件没有可检测到的G-to-A超突变，这表明一个或多个脱氨酶非依赖的L1限制机制。我们试图揭示APOBEC3C(A3C)介导的L1抑制的机制，发现它是不依赖脱氨酶的，需要一个完整的二聚位点，并且RNA结合口袋突变R122A取消了A3C对L1的限制。L1核糖核蛋白颗粒的密度梯度离心法、L1-ORF1p与A3C的亚细胞共定位和免疫共沉淀实验表明，L1 ORF1p与A3C二聚体之间依赖于RNA的物理相互作用是L1限制的关键。此外，我们证明了如果存在过表达的A3C，由L1逆转录酶合成的L1互补DNA量减少了∼50%。
LINE-1 (L1) retrotransposons are mobile genetic elements whose extensive proliferation resulted in the generation of ∼34% of the human genome. They have been shown to be a cause of single-gene diseases. Moreover, L1-encoded endonuclease can elicit double-strand breaks that may lead to genomic instability. Mammalian cells adopted strategies restricting mobility and deleterious consequences of uncontrolled retrotransposition. The human APOBEC3 protein family of polynucleotide cytidine deaminases contributes to intracellular defense against retroelements. APOBEC3 members inhibit L1 retrotransposition by 35–99%. However, genomic L1 retrotransposition events that occurred in the presence of L1-restricting APOBEC3 proteins are devoid of detectable G-to-A hypermutations, suggesting one or multiple deaminase-independent L1 restricting mechanisms. We set out to uncover the mechanism of APOBEC3C (A3C)-mediated L1 inhibition and found that it is deaminase independent, requires an intact dimerization site and the RNA-binding pocket mutation R122A abolishes L1 restriction by A3C. Density gradient centrifugation of L1 ribonucleoprotein particles, subcellular co-localization of L1-ORF1p and A3C and co-immunoprecipitation experiments indicate that an RNA-dependent physical interaction between L1 ORF1p and A3C dimers is essential for L1 restriction. Furthermore, we demonstrate that the amount of L1 complementary DNA synthesized by L1 reverse transcriptase is reduced by ∼50% if overexpressed A3C is present.
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影响因子：
3.5
作者：
Goodier, JL;Ostertag, EM;Kazazian, HH
通讯作者：
Kazazian, HH
DOI：
10.1073/pnas.0831042100
发表时间：
2003-04-29
影响因子：
11.1
作者：
Brouha, B;Schustak, J;Kazazian, HH
通讯作者：
Kazazian, HH
影响因子：
3.7
作者：
Bogerd, Hal P.;Wiegand, Heather L.;Cullen, Bryan R.
通讯作者：
Cullen, Bryan R.
影响因子：
16.6
作者：
Carmi, Shai;Church, George M.;Levanon, Erez Y.
通讯作者：
Levanon, Erez Y.
影响因子：
64.8
作者：
Chiu, YL;Soros, VB;Greene, WC
通讯作者：
Greene, WC