Involvement of stringent factor RelA in expression of the alkaline protease gene aprE in Bacillus subtilis
Involvement of stringent factor RelA in expression of the alkaline protease gene aprE in Bacillus subtilis
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DOI：
10.1128/jb.183.15.4648-4651.2001
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发表时间：
2001-08-01
影响因子：
3.2
通讯作者：
Tanaka, T
中科院分区：
文献类型：
--
作者：
Hata, M;Ogura, M;Tanaka, T
枯草芽孢杆菌aprE，编码细胞外碱性蛋白酶的表达，正调控磷酸化DegU，一个双组分调节系统，DegS-DegU的调节器。我们发现，在具有编码严格因子RelA的rclA突变的破坏突变体中，aprE“-”lacZ融合体的表达大大降低。在relA突变体中DegU的水平与野生型细胞中的水平相似。一个relA degU双突变没有导致进一步降低aprE '-' lacZ水平发现在degli单突变。在relA突变体中，aprE“-”lacZ融合体的表达被引起磷酸化DegU稳定的多拷贝degR或degU 32（Hy）和degS 200（Hy）突变刺激。此外，也依赖于磷酸化DegU的sacB“-”lacZ的表达被relA刺激。突变，并且这种刺激在relA degU双突变体中未观察到。这些结果表明RelA（或其产物鸟苷-3 '，5' -双二磷酸[pp Gpp]）不影响DegU的磷酸化，并提示其通过调节DegU依赖的转录参与aprE和sacB的表达。
Expression of Bacillus subtilis aprE, encoding an extracellular alkaline protease, is positively regulated by phosphorylated DegU, the regulator of a two-component regulatory system, DegS-DegU. We found that the expression of an aprE '-' lacZ fusion was greatly reduced in a disruption mutant with a mutation of rclA, which encodes the stringent factor RelA, The level of DegU in the relA mutant was similar to that in the wild-type cell. A relA degU double mutation did not result in a further decrease of the aprE '-' lacZ level found in a degli single mutant. The expression of the aprE'-'lacZ fusion in the relA mutant was stimulated by multicopy degR or the degU32(Hy) and degS200(Hy) mutations that cause the stabilization of phosphorylated DegU, Furthermore, the expression of sacB '-' lacZ, which is also dependent on phosphorylated DegU, was stimulated by the relA. mutation, and this stimulation was not seen in the relA degU double mutant. These results show that RelA (or its product guanosine-3 ' ,5 ' -bisdiphosphate [pp Gpp]) does not affect the phosphorylation of DegU and suggest that it participates in the expression of aprE and sacB through the regulation of DegU-dependent transcription.