A Vibrio cholerae LysR homolog, AphB, cooperates with AphA at the tcpPH promoter to activate expression of the ToxR virulence cascade
A Vibrio cholerae LysR homolog, AphB, cooperates with AphA at the tcpPH promoter to activate expression of the ToxR virulence cascade
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DOI：
10.1128/jb.181.14.4250-4256.1999
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发表时间：
1999-07-01
影响因子：
3.2
通讯作者：
Skorupski, K
中科院分区：
文献类型：
--
作者：
Kovacikova, G;Skorupski, K
我们在这里描述了转录调节因子 LysR 家族的一个新成员 AphB，它是霍乱弧菌 ToxR 毒力级联激活所必需的。 AphB 响应环境刺激而激活 tcpPH 操纵子的转录，这个过程需要与第二种蛋白质 AphA 的配合。 aphA 或 aphB 的表达均不受环境刺激的强烈调节，这增加了蛋白质本身的活性在各种条件下可能受到影响的可能性。 TI霍乱El Tor生物型菌株通常在体外表现出比经典菌株更孤独的ToxR调节毒力基因表达，并且需要特殊的培养条件（AKI培养基）来诱导高水平表达，我们在此表明，El Tor生物型菌株中tac启动子的aphB表达显着增加毒力基因表达，达到与在所有检查的生长条件下在经典菌株中观察到的水平相似的水平。这些结果表明AphB在毒力基因的差异调节中发挥作用两种致病生物型之间。
We describe here a new member of the LysR family of transcriptional regulators, AphB, which is required for activation of the Vibrio cholerae ToxR virulence cascade. AphB activates the transcription of the tcpPH operon in response to environmental stimuli, and this process requires cooperation with a second protein, AphA. The expression of neither aphA or aphB is strongly regulated by environmental stimuli, raising the possibility that the activities of the proteins themselves may be influenced under various conditions. Strains of the El Tor biotype of TI cholerae typically exhibit loner expression of ToxR-regulated virulence genes in vitro than classical strains and require specialized culture conditions (AKI medium) to induce high-level expression, We show here that expression of aphB from the tac promoter in El Tor biotype strains dramatically increases virulence gene expression to levels similar to those observed in classical strains under all growth conditions examined, These results suggest that AphB plays a role in the differential regulation of virulence genes between the two disease-causing biotypes.