Multiple regulators of Ty1 transposition in Saccharomyces cerevisiae have conserved roles in genome maintenance.
Multiple regulators of Ty1 transposition in Saccharomyces cerevisiae have conserved roles in genome maintenance.
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发表时间：
2001-12
期刊：
影响因子：
3.3
通讯作者：
D. Scholes;M. Banerjee;B. Bowen;M. Curcio
中科院分区：
文献类型：
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作者：
D. Scholes;M. Banerjee;B. Bowen;M. Curcio
酿酒酵母基因组中的大多数 Ty1 逆转录转座子具有转座能力，但很少进行转座。我们筛选了通过插入 mTn3-lacZ/LEU2 转座子诱变的酵母，以寻找导致 Ty1 cDNA 介导的迁移率升高的突变，这种突变是通过 cDNA 整合或重组而发生的。在这里，我们描述了 21 个 RTT（Ty1 转座调节）基因中 mTn3 插入的特征，这些基因导致 Ty1 迁移率增加 5 至 111 倍。这 21 个 RTT 基因是 EST2、RRM3、NUT2、RAD57、RRD2、RAD50、SGS1、TEL1、SAE2、MED1、MRE11、SCH9、KAP122 和 8 个以前未表征的基因。 RTT基因的破坏并没有显着增加Ty1 RNA水平，但确实提高了Ty1 cDNA水平，这表明大多数RTT基因产物在mRNA积累之后、cDNA整合之前的步骤中发挥作用。 rtt 突变对 Ty1 在首选靶位点的整合具有广泛不同的影响。 RTT101 和 NUT2 的突变显着刺激了 tRNA 基因上游的 Ty1 整合。相比之下，RRM3 的突变使 Ty1 的迁移率增加了 100 倍以上，但没有增加 tRNA 基因上游的整合。 Ty1 转座受基因组维持所需的基本途径成分的调节表明，Ty1 和酵母共同进化，将转座休眠与基因组的完整性联系起来。
Most Ty1 retrotransposons in the genome of Saccharomyces cerevisiae are transpositionally competent but rarely transpose. We screened yeast mutagenized by insertion of the mTn3-lacZ/LEU2 transposon for mutations that result in elevated Ty1 cDNA-mediated mobility, which occurs by cDNA integration or recombination. Here, we describe the characterization of mTn3 insertions in 21 RTT (regulation of Ty1 transposition) genes that result in 5- to 111-fold increases in Ty1 mobility. These 21 RTT genes are EST2, RRM3, NUT2, RAD57, RRD2, RAD50, SGS1, TEL1, SAE2, MED1, MRE11, SCH9, KAP122, and 8 previously uncharacterized genes. Disruption of RTT genes did not significantly increase Ty1 RNA levels but did enhance Ty1 cDNA levels, suggesting that most RTT gene products act at a step after mRNA accumulation but before cDNA integration. The rtt mutations had widely varying effects on integration of Ty1 at preferred target sites. Mutations in RTT101 and NUT2 dramatically stimulated Ty1 integration upstream of tRNA genes. In contrast, a mutation in RRM3 increased Ty1 mobility >100-fold without increasing integration upstream of tRNA genes. The regulation of Ty1 transposition by components of fundamental pathways required for genome maintenance suggests that Ty1 and yeast have coevolved to link transpositional dormancy to the integrity of the genome.