Co-ordinate regulation of Salmonella typhimurium invasion genes by environmental and regulatory factors is mediated by control of hilA expression
Co-ordinate regulation of Salmonella typhimurium invasion genes by environmental and regulatory factors is mediated by control of hilA expression
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DOI：
10.1046/j.1365-2958.1996.d01-1718.x
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发表时间：
1996-11-01
影响因子：
3.6
通讯作者：
Lee, CA
中科院分区：
文献类型：
--
作者：
Bajaj, V;Lucas, RL;Lee, CA
在感染宿主的过程中，沙门氏菌进入肠上皮细胞。已经提出，当鼠伤寒沙门氏菌存在于肠腔中时，几种环境和调节条件调节细菌进入宿主细胞所需的侵袭因子的表达。我们在这里报告的表达，六个不同的S。在沙门氏菌致病岛1（Salmonella pathogenicity island 1）上编码的鼠伤寒沙门氏菌（typhimurium）侵袭基因受氧、渗透压、pH、PhoPQ和HilA的协同调节，HilA是OmpR/ToxR家族的转录激活因子，其也在SPI 1上编码。在大肠杆菌中，HilA可激活报告质粒上的两个入侵基因-lacZY融合体的表达，表明HilA直接作用于S.鼠伤寒。我们已经发现，由氧，渗透压，pH值，和PhoPQ的入侵基因的调节是间接的，并通过这些环境和调节因子调节hilA的表达介导。我们推测，入侵基因的复杂和协调的调节，由HilA是一个重要的特征salmonella发病机制，并允许salmonella进入肠上皮细胞。
During infection of their hosts, salmonellae enter intestinal epithelial cells. It has been proposed that when Salmonella typhimurium is present in the intestinal lumen, several environmental and regulatory conditions modulate the expression of invasion factors required for bacterial entry into host cells. We report here that the expression of six different S. typhimurium invasion genes encoded on SPI1 (Salmonella pathogenicity island 1) is co-ordinately regulated by oxygen, osmolarity, pH, PhoPQ, and HilA, HilA is a transcriptional activator of the OmpR/ToxR family that is also encoded on SPI1, We have found that HiIA plays a central role in the co-ordinate regulation of invasion genes by environmental and regulatory conditions. HilA can activate the expression of two invasion gene-lacZY fusions on reporter plasmids in Escherichia coli, suggesting that HilA acts directly at invasion-gene promoters in S. typhimurium. We have found that the regulation of invasion genes by oxygen, osmolarity, pH, and PhoPQ is indirect and is mediated by regulation of hilA expression by these environmental and regulatory factors. We hypothesize that the complex and co-ordinate regulation of invasion genes by HilA is an important feature of salmonella pathogenesis and allows salmonellae to enter intestinal epithelial cells.