Host co-factors of the retrovirus-like transposon Ty1.
Host co-factors of the retrovirus-like transposon Ty1.
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DOI：
10.1186/1759-8753-3-12
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发表时间：
2012-08-02
期刊：
影响因子：
4.9
通讯作者：
Curcio MJ
中科院分区：
文献类型：
--
作者：
Risler JK;Kenny AE;Palumbo RJ;Gamache ER;Curcio MJ
长末端重复 (LTR) 反转录转座子具有复杂的移动模式，涉及细胞质病毒样颗粒 (VLP) 中 RNA 基因组的逆转录以及 cDNA 拷贝整合到宿主基因组中。逆转录转座子的编码能力有限，因此必须广泛依赖宿主辅助因子。然而，由于逆转录转座是一种罕见的事件，因此确定内源逆转录转座子迁移所需的辅助因子一直具有挑战性。为了规避酿酒酵母中 Ty1 LTR 逆转录转座子迁移率的低频率，我们使用迭代合成基因阵列 (SGA) 分析来分离减少逆转录转座的宿主突变。含有染色体 Ty1his3AI 报告元件和 rtt101Δ 或 med1Δ 突变（两者均赋予超转座表型）的查询菌株与 4,847 个单倍体 ORF 缺失菌株交配。在双突变子代中测量逆转录转座，并鉴定出一组 275 个 ORF 缺失，可抑制 rtt101Δ 和 med1Δ 的超转座表型。相应的 275 个逆转录宿主因子 (RHF) 组包括 45 个先前鉴定的 Ty1 或 Ty3 辅助因子。超过一半的 RHF 基因具有统计上稳健的人类同源物 (E < 1 x 10-10)。 181 个 rhfΔ 单突变体中未整合的 Ty1 cDNA 水平改变 <2 倍，表明相应的辅因子在 cDNA 合成后的一步刺激逆转录转座。然而，43个RHF基因的缺失，包括特定核糖体蛋白和核糖体生物合成基因以及RNA降解、修饰和转运基因，导致Ty1 cDNA水平较低。在核糖体生物发生突变体 bud21Δ、hcr1Δ、loc1Δ 和 puf6Δ 中，Ty1 Gag 水平降低，但 RNA 水平不降低。 Ty1 逆转录转座依赖于在复制周期的不同步骤发挥作用的多种辅因子。这些 RHF 的人类直系同源物是人类细胞中潜在的或在少数情况下推定的 HIV-1 辅助因子。缺失导致 Ty1 cDNA 减少的 RHF 基因包括特征性 RNA 代谢和修饰基因，这与它们在逆转录转座早期步骤（如 Ty1 RNA 的表达、核输出、翻译、定位或包装）中的作用一致。我们的结果表明 Bud21、Hcr1、Loc1 和 Puf6 促进 Ty1 Gag 的有效合成或稳定性。
Long-terminal repeat (LTR) retrotransposons have complex modes of mobility involving reverse transcription of their RNA genomes in cytoplasmic virus-like particles (VLPs) and integration of the cDNA copies into the host genome. The limited coding capacity of retrotransposons necessitates an extensive reliance on host co-factors; however, it has been challenging to identify co-factors that are required for endogenous retrotransposon mobility because retrotransposition is such a rare event. To circumvent the low frequency of Ty1 LTR-retrotransposon mobility in Saccharomyces cerevisiae, we used iterative synthetic genetic array (SGA) analysis to isolate host mutations that reduce retrotransposition. Query strains that harbor a chromosomal Ty1his3AI reporter element and either the rtt101Δ or med1Δ mutation, both of which confer a hypertransposition phenotype, were mated to 4,847 haploid ORF deletion strains. Retrotransposition was measured in the double mutant progeny, and a set of 275 ORF deletions that suppress the hypertransposition phenotypes of both rtt101Δ and med1Δ were identified. The corresponding set of 275 retrotransposition host factors (RHFs) includes 45 previously identified Ty1 or Ty3 co-factors. More than half of the RHF genes have statistically robust human homologs (E < 1 x 10-10). The level of unintegrated Ty1 cDNA in 181 rhfΔ single mutants was altered <2-fold, suggesting that the corresponding co-factors stimulate retrotransposition at a step after cDNA synthesis. However, deletion of 43 RHF genes, including specific ribosomal protein and ribosome biogenesis genes and RNA degradation, modification and transport genes resulted in low Ty1 cDNA levels. The level of Ty1 Gag but not RNA was reduced in ribosome biogenesis mutants bud21Δ, hcr1Δ, loc1Δ, and puf6Δ. Ty1 retrotransposition is dependent on multiple co-factors acting at different steps in the replication cycle. Human orthologs of these RHFs are potential, or in a few cases, presumptive HIV-1 co-factors in human cells. RHF genes whose absence results in decreased Ty1 cDNA include characterized RNA metabolism and modification genes, consistent with their having roles in early steps in retrotransposition such as expression, nuclear export, translation, localization, or packaging of Ty1 RNA. Our results suggest that Bud21, Hcr1, Loc1, and Puf6 promote efficient synthesis or stability of Ty1 Gag.
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影响因子：
4.5
作者：
Coombes, CE;Boeke, JD
通讯作者：
Boeke, JD
影响因子：
10.5
作者：
Fujii, Kotaro;Kitabatake, Makoto;Ohno, Mutsuhito
通讯作者：
Ohno, Mutsuhito
DOI：
10.1073/pnas.88.3.936
发表时间：
1991-02-01
影响因子：
11.1
作者：
CURCIO, MJ;GARFINKEL, DJ
通讯作者：
GARFINKEL, DJ
影响因子：
7
作者：
Baller, Joshua A.;Gao, Jiquan;Voytas, Daniel F.
通讯作者：
Voytas, Daniel F.
影响因子：
64.8
作者：
Dragon, F;Gallagher, JEG;Baserga, SJ
通讯作者：
Baserga, SJ