Yeast telomeres exert a position effect on recombination between internal tracts of yeast telomeric DNA.
Yeast telomeres exert a position effect on recombination between internal tracts of yeast telomeric DNA.
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酵母端粒对酵母端粒DNA内束之间的重组发挥位置效应。
DOI：
10.1101/gad.12.19.3044
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发表时间：
1998
影响因子：
10.5
通讯作者：
Zakian,VA
中科院分区：
文献类型：
--
作者：
Stavenhagen,JB;Zakian,VA
在酿酒酵母中，端粒的邻近影响相邻DNA的转录和复制。在这项研究中，我们表明，端粒也施加有丝分裂重组的位置效应。端粒C1-3A/TG 1 -3DNA的直接重复片段之间的重组率由于接近端粒而严重降低。相反，重组的两个控制基板不受端粒接近。因此，与位置对转录或复制的影响不同，重组的抑制是序列特异性的。此外，重组的抑制与转录抑制（端粒位置效应; TPE）不受相同的控制，因为TPE所必需的基因突变不会减轻重组的端粒抑制。端粒附近C1-3A/TG 1 - 3 tracts之间重组的减少是由于缺乏Rad 52 p依赖性事件以及Rad 1 p依赖性事件的减少所致。在过度表达端粒结合蛋白Rap 1 p的细胞中，端粒附近重组的序列特异性抑制被消除，这种情况也增加了染色体内部位置C1-3A/TG 1 - 3 tracts之间的重组。我们认为，端粒附近的C1-3A/TG 1 - 3 tracts之间的特异性抑制是通过端粒特异性末端结合蛋白的作用发生的，该蛋白结合重组中间体加工过程中产生的单链TG 1 - 3 tail。重组抑制蛋白还可以阻断内源性端粒之间的重组。
InSaccharomyces cerevisiae, proximity to a telomere affects both transcription and replication of adjacent DNA. In this study, we show that telomeres also impose a position effect on mitotic recombination. The rate of recombination between directly repeated tracts of telomeric C1–3A/TG1–3DNA was reduced severely by proximity to a telomere. In contrast, recombination of two control substrates was not affected by telomere proximity. Thus, unlike position effects on transcription or replication, inhibition of recombination was sequence specific. Moreover, the repression of recombination was not under the same control as transcriptional repression (telomere position effect; TPE), as mutations in genes essential for TPE did not alleviate telomeric repression of recombination. The reduction in recombination between C1–3A/TG1–3tracts near the telomere was caused by an absence of Rad52p-dependent events as well as a reduction in Rad1p-dependent events. The sequence-specific repression of recombination near the telomere was eliminated in cells that overexpressed the telomere-binding protein Rap1p, a condition that also increased recombination between C1–3A/TG1–3tracts at internal positions on the chromosome. We propose that the specific inhibition between C1–3A/TG1–3tracts near the telomere occurs through the action of a telomere-specific end-binding protein that binds to the single-strand TG1–3tail generated during the processing of recombination intermediates. The recombination inhibitor protein may also block recombination between endogenous telomeres.