Le Thuong Ngoc, Wagner Alexander, Albers Sonja-Verena
Molecular Biology of Archaea, Institute of Biology II - Microbiology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany.
Microbiology (Reading). 2017 May;163(5):778-788. doi: 10.1099/mic.0.000455. Epub 2017 May 3.
Upon DNA damage, Sulfolobales exhibit a global gene regulatory response resulting in the expression of DNA transfer and repair proteins and the repression of the cell division machinery. Because the archaeal DNA damage response is still poorly understood, we investigated the promoters of the highly induced ups operon. Ups pili are involved in cellular aggregation and DNA exchange between cells. With LacS reporter gene assays we identified a conserved, non-palindromic hexanucleotide motif upstream of the ups core promoter elements to be essential for promoter activity. Substitution of this cis regulatory motif in the ups promoters resulted in abolishment of cellular aggregation and reduced DNA transfer. By screening the Sulfolobus acidocaldarius genome we identified a total of 214 genes harbouring the hexanucleotide motif in their respective promoter regions. Many of these genes were previously found to be regulated upon UV light treatment. Given the fact that the identified motif is conserved among S. acidocaldarius and Sulfolobus tokodaii promoters, we speculate that a common regulatory mechanism is present in these two species in response to DNA-damaging conditions.
在DNA损伤时，硫化叶菌展现出一种全局基因调控反应，导致DNA转移和修复蛋白的表达以及细胞分裂机制的抑制。由于古菌的DNA损伤反应仍知之甚少，我们研究了高度诱导的ups操纵子的启动子。Ups菌毛参与细胞聚集和细胞间的DNA交换。通过LacS报告基因检测，我们确定了ups核心启动子元件上游一个保守的、非回文六核苷酸基序对启动子活性至关重要。在ups启动子中替换这个顺式调控基序导致细胞聚集消失和DNA转移减少。通过筛选嗜酸硫化叶菌基因组，我们总共鉴定出214个在各自启动子区域含有六核苷酸基序的基因。其中许多基因先前已被发现受紫外线处理调控。鉴于所鉴定的基序在嗜酸硫化叶菌和嗜热栖热硫化叶菌的启动子中保守，我们推测这两个物种在应对DNA损伤条件时存在一种共同的调控机制。
