Mechanotransduction and contact inhibition (CI) control gene expression to regulate proliferation, differentiation, and even tumorigenesis of cells. However, their downstream trans-acting factors (TAFs) are not well known due to a lack of a high-throughput method to quantitatively detect them. Here, we developed a method to identify TAFs on the cis-acting sequences that reside in open chromatin or DNaseI-hypersensitive sites (DHSs) and to detect nucleocytoplasmic shuttling TAFs using computational and experimental screening. The DHS-proteomics revealed over 1000 potential mechanosensing TAFs and UBE2A/B (Ubiquitin-conjugating enzyme E2 A) was experimentally identified as a force- and CI-dependent nucleocytoplasmic shuttling TAF. We found that translocation of YAP/TAZ and UBE2A/B are distinctively regulated by inhibition of myosin contraction, actin-polymerization, and CI depending on cell types. Next-generation sequence analysis revealed many downstream genes including YAP are transcriptionally regulated by ubiquitination of histone by UBE2A/B. Our results suggested a YAP-independent mechanotransduction and CI pathway mediated by UBE2A/B.

中文翻译：

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UBE2A/B 是介导机械传导和接触抑制的反式作用因子

力转导和接触抑制（CI）控制基因表达，调节细胞的增殖、分化，甚至肿瘤发生。然而，由于缺乏定量检测它们的高通量方法，它们的下游反式作用因子（TAF）并不为人所知。在这里，我们开发了一种方法来识别位于开放染色质或 DNaseI 超敏感位点 (DHS) 的顺式作用序列上的 TAF，并使用计算和实验筛选来检测核质穿梭 TAF。DHS 蛋白质组学揭示了超过 1000 个潜在的机械传感 TAF，UBE2A/B（泛素结合酶 E2 A）经实验鉴定为力和 CI 依赖性核细胞质穿梭 TAF。我们发现，根据细胞类型，YAP/TAZ 和 UBE2A/B 的易位受到肌球蛋白收缩、肌动蛋白聚合和 CI 的抑制的独特调节。下一代序列分析显示，包括 YAP 在内的许多下游基因通过 UBE2A/B 对组蛋白的泛素化进行转录调节。我们的结果表明，UBE2A/B 介导了不依赖于 YAP 的机械转导和 CI 途径。