Expression of chaA, a sodium ion extrusion system of Escherichia coli, is regulated by osmolarity and pH.
Expression of chaA, a sodium ion extrusion system of Escherichia coli, is regulated by osmolarity and pH.
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DOI：
10.1016/s0005-2728(02)00345-6
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发表时间：
2002-12
期刊：
影响因子：
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通讯作者：
T. Shijuku;T. Yamashino;Hyuma Ohashi;H. Saito;T. Kakegawa;M. Ohta;Hiroshi Kobayashi
中科院分区：
文献类型：
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作者：
T. Shijuku;T. Yamashino;Hyuma Ohashi;H. Saito;T. Kakegawa;M. Ohta;Hiroshi Kobayashi
ChaA是大肠杆菌的一种钠离子挤出系统，在高pH下也能发挥作用[biochem]。Biophys。学报1363(1998)231]。利用大肠杆菌O157:H7的chaA构建了chaA - lacz转录融合基因，并在大肠杆菌K12衍生菌株中进行了表达。融合基因在高pH条件下表达，可通过添加NaCl、KCl或蔗糖诱导。逆转录聚合酶链反应（RT-PCR）检测的chaA mRNA的数量随着蔗糖的添加而增加。这些结果表明，chaA的表达受介质渗透压和pH的调节。
ChaA, one of the sodium ion extrusion systems of Escherichia coli, was found to function at high pH [Biochim. Biophys. Acta 1363 (1998) 231]. A chaA–lacZ transcriptional fusion gene was constructed using chaA of E. coli O157:H7 and its expression was observed in strains derived from E. coli K12. The fusion gene was expressed at high pH and was induced by the addition of NaCl, KCl or sucrose. The amount of chaA mRNA measured by reverse transcription-polymerase chain reaction (RT-PCR) was increased by the addition of sucrose to alkaline growth medium. These results suggested that chaA expression was regulated by medium osmolarity and pH.