Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
German Center of Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany.
Sci Rep. 2020 Nov 5;10(1):19079. doi: 10.1038/s41598-020-76193-0.
Zinc finger proteins (ZNF) are a large group of transcription factors with diverse functions. We recently discovered that endothelial cells harbour a specific mechanism to limit the action of ZNF354C, whose function in endothelial cells is unknown. Given that ZNF354C has so far only been studied in bone and tumour, its function was determined in endothelial cells. ZNF354C is expressed in vascular cells and localises to the nucleus and cytoplasm. Overexpression of ZNF354C in human endothelial cells results in a marked inhibition of endothelial sprouting. RNA-sequencing of human microvascular endothelial cells with and without overexpression of ZNF354C revealed that the protein is a potent transcriptional repressor. ZNF354C contains an active KRAB domain which mediates this suppression as shown by mutagenesis analysis. ZNF354C interacts with dsDNA, TRIM28 and histones, as observed by proximity ligation and immunoprecipitation. Moreover, chromatin immunoprecipitation revealed that the ZNF binds to specific endothelial-relevant target-gene promoters. ZNF354C suppresses these genes as shown by CRISPR/Cas knockout and RNAi. Inhibition of endothelial sprouting by ZNF354C is dependent on the amino acids DV and MLE of the KRAB domain. These results demonstrate that ZNF354C is a repressive transcription factor which acts through a KRAB domain to inhibit endothelial angiogenic sprouting.
锌指蛋白（ZNF）是一大类具有多种功能的转录因子。我们最近发现，内皮细胞具有一种特定的机制来限制 ZNF354C 的作用，而 ZNF354C 在内皮细胞中的功能尚不清楚。鉴于 ZNF354C 迄今为止仅在骨骼和肿瘤中进行了研究，因此我们在内皮细胞中确定了其功能。ZNF354C 在血管细胞中表达，定位于细胞核和细胞质。在人内皮细胞中过表达 ZNF354C 会导致内皮芽生明显受到抑制。用和不用 ZNF354C 过表达的人微血管内皮细胞进行 RNA 测序显示，该蛋白是一种有效的转录抑制因子。ZNF354C 含有一个活性 KRAB 结构域，如突变分析所示，该结构域介导了这种抑制。ZNF354C 与 dsDNA、TRIM28 和组蛋白相互作用，如接近连接和免疫沉淀所观察到的。此外，染色质免疫沉淀显示 ZNF 与特定的内皮相关靶基因启动子结合。CRISPR/Cas 敲除和 RNAi 显示，ZNF 抑制这些基因。ZNF354C 通过 KRAB 结构域抑制内皮细胞发芽，这取决于 KRAB 结构域的氨基酸 DV 和 MLE。这些结果表明，ZNF354C 是一种抑制性转录因子，通过 KRAB 结构域抑制内皮细胞血管生成芽生。
