Pch2 is an AAA+ protein that controls DNA break formation, recombination and checkpoint signaling during meiotic G2/prophase. Chromosomal association of Pch2 is linked to these processes, and several factors influence the association of Pch2 to euchromatin and the specialized chromatin of the ribosomal (r)DNA array of budding yeast. Here, we describe a comprehensive mapping of Pch2 localization across the budding yeast genome during meiotic G2/prophase. Within non-rDNA chromatin, Pch2 associates with a subset of actively RNA Polymerase II (RNAPII)-dependent transcribed genes. Chromatin immunoprecipitation (ChIP)- and microscopy-based analysis reveals that active transcription is required for chromosomal recruitment of Pch2. Similar to what was previously established for association of Pch2 with rDNA chromatin, we find that Orc1, a component of the Origin Recognition Complex (ORC), is required for the association of Pch2 to these euchromatic, transcribed regions, revealing a broad connection between chromosomal association of Pch2 and Orc1/ORC function. Ectopic mitotic expression is insufficient to drive recruitment of Pch2, despite the presence of active transcription and Orc1/ORC in mitotic cells. This suggests meiosis-specific ‘licensing’ of Pch2 recruitment to sites of transcription, and accordingly, we find that the synaptonemal complex (SC) component Zip1 is required for the recruitment of Pch2 to transcription-associated binding regions. Interestingly, Pch2 binding patterns are distinct from meiotic axis enrichment sites (as defined by Red1, Hop1, and Rec8). Inactivating RNAPII-dependent transcription/Orc1 does not lead to effects on the chromosomal abundance of Hop1, a known chromosomal client of Pch2, suggesting a complex relationship between SC formation, Pch2 recruitment and Hop1 chromosomal association. We thus report characteristics and dependencies for Pch2 recruitment to meiotic chromosomes, and reveal an unexpected link between Pch2, SC formation, chromatin and active transcription.

Pch2是AAA +蛋白质，可控制减数分裂G2 /前期过程中DNA断裂的形成，重组和检查点信号传导。Pch2的染色体缔合与这些过程相关，并且有几个因素影响Pch2与正染色质和萌芽酵母核糖体（r）DNA阵列的专门染色质的缔合。在这里，我们描述了减数分裂G2 /前期过程中，Pch2定位在发芽酵母基因组中的全面定位。在非rDNA染色质中，Pch2与主动RNA聚合酶II（RNAPII）依赖性转录基因的子集相关联。染色质免疫沉淀（ChIP）和基于显微镜的分析表明，Pch2的染色体募集需要主动转录。与先前建立的将Pch2与rDNA染色质缔合的相似，我们发现Orc1，Pch2与这些常色转录区的缔合需要起源识别复合物（ORC）的一个组成部分，从而揭示了Pch2的染色体缔合与Orc1 / ORC功能之间的广泛联系。尽管有丝分裂细胞中存在主动转录和Orc1 / ORC，但异位有丝分裂表达不足以驱动Pch2募集。这表明Pch2募集到转录位点的减数分裂特异性“许可”，因此，我们发现突触复合体（SC）组件Zip1是Pch2募集到转录相关结合区域所必需的。有趣的是，Pch2的结合模式与减数分裂轴富集位点不同（如Red1，Hop1和Rec8所定义）。灭活依赖于RNAPII的转录/ Orc1不会对Hop1（已知的Pch2染色体客户）Hop1的染色体丰度产生影响，表明SC形成，Pch2募集和Hop1染色体关联之间存在复杂的关系。因此，我们报告特征和Pch2募集到减数分裂染色体的依赖性，并揭示Pch2，SC形成，染色质和活性转录之间的意外链接。