Dysregulation of serine biosynthesis contributes to the growth defect of a Mycobacterium tuberculosis crp mutant.
Dysregulation of serine biosynthesis contributes to the growth defect of a Mycobacterium tuberculosis crp mutant.
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DOI：
10.1111/j.1365-2958.2011.07806.x
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发表时间：
2011-10
影响因子：
3.6
通讯作者：
McDonough KA
中科院分区：
文献类型：
--
作者：
Bai G;Schaak DD;Smith EA;McDonough KA
由Rv3676 （crp）编码的结核分枝杆菌CRPMt是一种与serC - Rv0885基因间区结合的类crp转录因子。在本研究中，我们利用位点特异性突变、启动子融合和RT-PCR技术评估了CRPMt对结核分枝杆菌和牛分枝杆菌中serC和Rv0885的调控作用。CRPMt结合位点是serC和Rv0885完全表达所必需的，结核分枝杆菌和牛分枝杆菌BCG crp突变体中这两个基因的表达均降低。这些数据表明，CRPMt结合直接激活了serC和Rv0885的表达。结核分枝杆菌血清c恢复了大肠杆菌血清c突变体在无丝氨酸培养基中生长的能力，证明结核分枝杆菌血清c编码磷酸丝氨酸转氨酶。丝氨酸补充或serC的过度表达加速了结核分枝杆菌和牛分枝杆菌BCG crp突变体在支原体中的生长，但在巨噬细胞中没有。这些结果证实了CRPMt在氨基酸生物合成中的调控作用，并表明丝氨酸产生的减少有助于结核分枝杆菌和牛分枝杆菌BCG crp突变体的体外生长缓慢表型。通过serC表达恢复丝氨酸生物合成将有助于鉴定巨噬细胞和宿主感染期间结核分枝杆菌所需的其他crpmt调节因子。
Mycobacterium tuberculosis CRPMt, encoded by Rv3676 (crp), is a CRP-like transcription factor that binds with the serC – Rv0885 intergenic region. In the present study, we evaluated CRPMt’s regulation of serC and Rv0885 in M. tuberculosis and M. bovis BCG, using site-specific mutagenesis, promoter fusions and RT-PCR. The CRPMt binding site was required for full expression of serC and Rv0885, and expression of both genes was reduced in M. tuberculosis and M. bovis BCG crp mutants. These data show that CRPMt binding directly activates both serC and Rv0885 expression. M. tuberculosis serC restored the ability of an Escherichia coli serC mutant to grow in serine-dropout medium, demonstrating that M. tuberculosis serC encodes a phosphoserine aminotransferase. Serine supplementation, or overexpression of serC, accelerated the growth of M. tuberculosis and M. bovis BCG crp mutants in mycomedium, but not within macrophages. These results establish a role for CRPMt in the regulation of amino acid biosynthesis, and show that reduced serine production contributes to the slow-growth phenotype of M. tuberculosis and M. bovis BCG crp mutants in vitro. Restoration of serine biosynthesis by serC expression will facilitate identification of additional CRPMt-regulated factors required by M. tuberculosis during macrophage and host infection.
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影响因子：
2.8
作者：
Agarwal, Nisheeth;Raghunand, Tirumalai R.;Bishai, William R.
通讯作者：
Bishai, William R.
影响因子：
3.2
作者：
Gazdik, MA;McDonough, KA
通讯作者：
McDonough, KA
影响因子：
3.2
作者：
CLARKE, SJ;LOW, B;KONIGSBERG, WH
通讯作者：
KONIGSBERG, WH
影响因子：
3.1
作者：
Caler, EV;Morty, RE;Andrews, NW
通讯作者：
Andrews, NW
影响因子：
2.8
作者：
Bardarov, S;Bardarov, S;Jacobs, WR
通讯作者：
Jacobs, WR