Hypermutation of ApoB mRNA by rat APOBEC-1 overexpression mimics APOBEC-3 hypermutation.
Hypermutation of ApoB mRNA by rat APOBEC-1 overexpression mimics APOBEC-3 hypermutation.
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DOI：
10.1016/j.jmb.2012.02.005
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发表时间：
2012-04-20
影响因子：
5.6
通讯作者：
Patterson, Amy P.
中科院分区：
文献类型：
--
作者：
Chen, Zhigang;Eggerman, Thomas L.;Bocharov, Alexander V.;Baranova, Irina N.;Vishnyakova, Tatyana G.;Kurlander, Roger J.;Csako, Gyorgy;Patterson, Amy P.
APOBEC - 3蛋白在多种病毒的病毒基因组中诱导C到U的超突变，并具有广泛的抗病毒活性。一般来说，只有一小部分病毒基因组（≤10⁻²）被APOBEC - 3蛋白超突变，但往往有许多胞嘧啶（高达40%）被转化为尿嘧啶。这种独特的选择性超突变机制仍然未知。我们发现大鼠APOBEC - 1的过表达在其底物apoB mRNA上具有与APOBEC - 3蛋白相似的超突变模式。大鼠APOBEC - 1的瞬时质粒转染导致在HepG2和McA7777细胞中apoB mRNA分别有0.4%和1.8%的超突变。通过在72 - 76°C下进行3D - PCR富集了低频的超突变apoB mRNA靶点，超突变水平提高到67%。在超突变的apoB mRNA中，HepG2细胞中高达69.6%的胞嘧啶和McA7777细胞中75.5%的胞嘧啶被转化为尿嘧啶。当大鼠APOBEC - 1通过腺病毒过表达时，apoB mRNA的超突变频率从0.4%增加到约20%，并且通过常规PCR很容易检测到。然而，这种更高的表达效率只是增加了超突变的频率，而不是超突变靶点中受影响的胞嘧啶的数量。大鼠APOBEC - 1的超突变受辅因子调节，并且被E181Q突变消除，这表明辅因子在超突变中的作用。在大鼠APOBEC - 1中发现APOBEC - 3超突变模式表明辅因子也可能参与APOBEC - 3的超突变。利用乙肝病毒超突变，我们发现KSRP增加了APOBEC - 3C和 - 3B的超突变。这些数据表明，与大鼠APOBEC - 1超突变一样，细胞因子可能在APOBEC - 3超突变中起调节作用。
APOBEC-3 proteins induce C-to-U hypermutations in the viral genome of various viruses and have broad antiviral activity. Generally only a small proportion of viral genomes (≤10−2) are hypermutated by APOBEC-3s but often many cytidines (up to 40%) are converted to uridine. The mechanism of this unique selective hypermutation remains unknown. We found that rat APOBEC-1 over-expression had a hypermutation pattern similar to APOBEC-3s on its substrate apoB mRNA. Transient plasmid transfection of rat APOBEC-1 resulted in 0.4% and 1.8% hypermutations with apoB mRNA in HepG2 and McA7777 cells, respectively. The low frequency of hypermutated apoB mRNA targets was enriched by 3D-PCR at 72–76°C with hypermutation levels increasing up to 67%. Up to 69.6% of cytidines in HepG2 and 75.5% in McA7777 cells were converted to uridines in the hypermutated apoB mRNA. When rat APOBEC-1 was over-expressed by adenovirus, the hypermutation frequency of apoB mRNA increased from 0.4% to ~20% and was readily detected by regular PCR. However, this higher expression efficiency only increased the frequency of hypermutation, not the number of affected cytidines in the hypermutated targets. Rat APOBEC-1 hypermutation was modulated by cofactors and was eliminated by an E181Q mutation, indicating the role of cofactors in the hypermutation. The finding of an APOBEC-3 hypermutation pattern with rat APOBEC-1 suggests that cofactors could also be involved in APOBEC-3 hypermutation. Utilizing HBV hypermutation, we found that KSRP increased APOBEC-3C and -3B hypermutation. These data show that like rat APOBEC-1 hypermutation, cellular factors may play a regulatory role on APOBEC-3 hypermutation.
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影响因子：
64.5
作者：
Harris, RS;Bishop, KN;Malim, MH
通讯作者：
Malim, MH
影响因子：
5.6
作者：
Petit, Vincent;Guetard, Denise;Vartanian, Jean-Pierre
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Vartanian, Jean-Pierre
影响因子：
64.8
作者：
Sheehy, AM;Gaddis, NC;Malim, MH
通讯作者：
Malim, MH
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56.9
作者：
CHEN, SH;HABIB, G;CHAN, L
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CHAN, L
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3.7
作者：
Browne, Edward P.;Allers, Carolina;Landau, Nathaniel R.
通讯作者：
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