Expression and localization of the Mycobacterium tuberculosis protein tyrosine phosphatase PtpA
Expression and localization of the Mycobacterium tuberculosis protein tyrosine phosphatase PtpA
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DOI：
10.1016/s0923-2508(02)01309-8
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发表时间：
2002-05-01
影响因子：
2.6
通讯作者：
Av-Gay, Y
中科院分区：
文献类型：
--
作者：
Cowley, SC;Babakaiff, R;Av-Gay, Y
结核分枝杆菌开放阅读框Rv2234编码一种低分子量酪氨酸磷酸酶PtpA。PtpA活性的动力学分析表明，它能够对磷酸对硝基苯基以及多种含磷酸酪氨酸的底物进行去磷酸化。相比之下，PtpA对含有磷丝氨酸或-苏氨酸残基的底物没有可检测到的活性。转录分析显示结核分枝杆菌ptpA启动子在生长缓慢的牛分枝杆菌卡介苗中表达，而在生长迅速的耻垢分枝杆菌中不表达。此外，ptpA的表达在卡介苗培养物进入固定期时上调，在人单核细胞感染时增加。我们还发现，尽管缺乏一般的输出通路信号序列，结核分枝杆菌PtpA蛋白在生长过程中可以从结核分枝杆菌和耻垢分枝杆菌中释放出来。(C) 2002年版《科学与医学》Elsevier SAS。版权所有。
The Mycobacterium tuberculosis open reading frame Rv2234 encodes a low molecular weight tyrosine phosphatase named PtpA. Kinetic analyses of PtpA activity reveal that it is capable of dephosphorylation of p-nitrophenyl phosphate, as well as a variety of phosphotyrosine-containing substrates. In contrast, PtpA showed no detectable activity towards substrates containing phosphoserine or -threonine residues. Transcriptional analysis reveals that the M. tuberculosis ptpA promoter is expressed in the slow-growing Mycobacterium species M. bovis BCG, but not in the fast-growing species M. smegmatis. Furthermore, ptpA expression is upregulated upon entry of BCG cultures into stationary phase and increases upon infection of human monocytes. We also show that, despite the lack of a general export pathway signal sequence, the M. tuberculosis PtpA protein can be released from both M. tuberculosis and M. smegmatis during growth. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.