Rhomboid protease AarA mediates quorum-sensing in Providencia stuartii by activating TatA of the twin-arginine translocase
Rhomboid protease AarA mediates quorum-sensing in Providencia stuartii by activating TatA of the twin-arginine translocase
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DOI：
10.1073/pnas.0608140104
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发表时间：
2007-01-16
影响因子：
11.1
通讯作者：
Rather, Philip N.
中科院分区：
文献类型：
--
作者：
Stevenson, Lindsay G.;Strisovsky, Kvido;Rather, Philip N.
stuartii aara蛋白是膜内丝氨酸蛋白酶的菱形家族的成员，是产生未知的群体感应分子所必需的。在屏幕中以鉴定来自Proteus mirabilis的菱形编码基因，塔塔被鉴定为多拷贝抑制器，并恢复了细胞外信号的产生，并补充了Prov的所有其他表型。 Stuartii Aara突变体。塔塔是双精氨酸易位酶（TAT）蛋白分泌途径的组成部分，可能形成分泌孔。相比之下，Prov的本地TATA基因。多拷贝中的Stuartii不会抑制AARA突变。我们在Prov中找到了Tata。 Stuartii具有短的N末端延伸，这是来自大多数其他细菌的TATA蛋白质的非典型延伸。 AARA在体内和体外都可以蛋白水解去除该延伸。一个省。 Stuartii tata蛋白缺少前7个AA恢复了营救AARA依赖性表型的能力。为了验证TAT系统的丢失是AARA突变体所表现出的各种表型的原因，构建了TATC-NULL等位基因。 TATC突变体表现出与AARA突变体相同的表型，并且对Aara表示同意。这些数据为AARA在法定语中的要求提供了分子解释，并在生产分泌的信号分子的产生中发现了TAT蛋白导出系统的功能。最后，TATA代表了原核生物菱形蛋白酶的经过验证的自然底物。
The Providencia stuartii AarA protein is a member of the rhomboid family of intramembrane serine proteases and is required for the production of an unknown quorum-sensing molecule. In a screen to identify rhomboid-encoding genes from Proteus mirabilis, tatA was identified as a multicopy suppressor and restored extracellular signal production as well as complementing all other phenotypes of a Prov. stuartii aarA mutant. TatA is a component of the twin-arginine translocase (Tat) protein secretion pathway and likely forms a secretion pore. By contrast, the native tatA gene of Prov. stuartii in multicopy did not suppress an aarA mutation. We find that TatA in Prov. stuartii has a short N-terminal extension that was atypical of TatA proteins from most other bacteria. This extension was proteolytically removed by AarA both in vivo and in vitro. A Prov. stuartii TatA protein missing the first 7 aa restored the ability to rescue the aarA-dependent phenotypes. To verify that loss of the Tat system was responsible for the various phenotypes exhibited by an aarA mutant, a tatC-null allele was constructed. The tatC mutant exhibited the same phenotypes as an aarA mutant and was epistatic to aarA. These data provide a molecular explanation for the requirement of AarA in quorum-sensing and uncover a function for the Tat protein export system in the production of secreted signaling molecules. Finally, TatA represents a validated natural substrate for a prokaryotic rhomboid protease.