Condensin is an essential component of chromosome dynamics, including mitotic chromosome condensation and segregation, DNA repair, and development. Genome-wide localization of condensin is known to correlate with transcriptional activity. The functional relationship between condensin accumulation and transcription sites remains unclear, however. By constructing the auxin-inducible degron strain of condensin, herein we demonstrate that condensin does not affect transcription itself. Instead, RNA processing at transcriptional termination appears to define condensin accumulation sites during mitosis, in the fission yeast Schizosaccharomyces pombe. Combining the auxin-degron strain with the nda3 β-tubulin cold-sensitive (cs) mutant enabled us to inactivate condensin in mitotically arrested cells, without releasing the cells into anaphase. Transcriptional activation and termination were not affected by condensin's degron-mediated depletion, at heat-shock inducible genes or mitotically activated genes. On the other hand, condensin accumulation sites shifted approximately 500 bp downstream in the auxin-degron of 5'-3' exoribonuclease Dhp1, in which transcripts became aberrantly elongated, suggesting that condensin accumulates at transcriptionally terminated DNA regions. Growth defects in mutant strains of 3'-processing ribonuclease and polyA cleavage factors were additive in condensin temperature-sensitive (ts) mutants. Considering condensin's in vitro activity to form double-stranded DNAs from unwound, single-stranded DNAs or DNA-RNA hybrids, condensin-mediated processing of mitotic transcripts at the 3'-end may be a prerequisite for faithful chromosome segregation.

中文翻译：

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凝缩蛋白位于有丝分裂的转录终止位点，可能释放有丝分裂的转录本。

凝集素是染色体动力学的重要组成部分，包括有丝分裂染色体的凝结和分离，DNA修复和发育。凝缩蛋白在全基因组中的定位与转录活性相关。然而，凝集素积累与转录位点之间的功能关系尚不清楚。通过构建凝集素的生长素诱导型德隆菌株，我们在这里证明了凝缩蛋白本身不会影响转录。取而代之的是，在裂殖酵母粟酒裂殖酵母中，转录终止处的RNA处理似乎在有丝分裂过程中定义了凝集素积累位点。将生长素-德隆菌株与nda3β-微管蛋白冷敏（cs）突变体结合在一起使我们能够灭活有丝分裂阻滞细胞中的凝集素，而无需将细胞释放到后期。在热休克诱导基因或有丝分裂激活基因上，凝集素的地龙介导的耗竭不影响转录激活和终止。另一方面，在5'-3'外切核糖核酸酶Dhp1的生长素-德隆区中，凝缩蛋白积累位点向下游移动约500 bp，其中转录物异常变长，表明凝缩蛋白积累在转录终止的DNA区域。3'加工核糖核酸酶和polyA裂解因子的突变菌株中的生长缺陷是冷凝蛋白温度敏感（ts）突变体的加性。考虑到凝集素的体外活性，该酶从解链的单链DNA或DNA-RNA杂合物形成双链DNA，在3'端凝缩蛋白介导的有丝分裂转录本的加工