The Agrobacterium tumefaciens vir gene transcriptional activator virG is transcriptionally induced by acid pH and other stress stimuli
The Agrobacterium tumefaciens vir gene transcriptional activator virG is transcriptionally induced by acid pH and other stress stimuli
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根癌农杆菌 vir 基因转录激活子 virG 由酸性 pH 值和其他应激刺激转录诱导
DOI：
10.1128/jb.174.4.1189-1196.1992
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发表时间：
1992
影响因子：
3.2
通讯作者：
S. C. Winans
中科院分区：
文献类型：
--
作者：
N. Mantis;S. C. Winans
在植物感染过程中，VirA和VirG蛋白协同诱导一组致病所需的根癌农杆菌操纵子。VirG的细胞内浓度增加响应于酸性介质，并提出了这种响应在转录水平上的启动子（P2），类似于大肠杆菌热休克启动子进行调节。为了验证这一假设，我们首先构建了virG-lacZ转录融合体。含有这种融合的菌株有较高水平的β-半乳糖苷酶活性在酸性介质中比在中性pH的介质。第二，引物延伸分析virG表明，酸性介质刺激该启动子的转录。为了确定P2是否是A. tumefaciens、5种诱导E. coli热激基因在A.根瘤菌P2是最强烈的低pH值诱导，中度刺激氯化镉或丝裂霉素C，并轻微诱导P2 β-半乳糖苷酶活性和引物延伸分析所测量。通过这些处理的诱导不需要任何Ti质粒编码的功能或染色体编码的RecA蛋白。我们还脉冲标记细胞蛋白后，转移到低pH值，并检测到几种蛋白质的合成诱导这些条件。我们的结论是，P2主要是由酸性pH值和次要的某些其他刺激，其中每一个是紧张的细胞生长诱导。这种应激诱导至少部分独立于热休克和SOS反应。
A set of Agrobacterium tumefaciens operons required for pathogenesis is coordinately induced during plant infection by the VirA and VirG proteins. The intracellular concentration of VirG increases in response to acidic media, and this response was proposed to be regulated at the level of transcription at a promoter (P2) that resembles the Escherichia coli heat shock promoters. To test this hypothesis, we first constructed a virG-lacZ transcriptional fusion. A strain containing this fusion had higher levels of beta-galactosidase activity in acidic media than in media at neutral pH. Second, primer extension analysis of virG indicated that acidic media stimulated the transcription of this promoter. To determine whether P2 is a member of a heat shock-like regulon in A. tumefaciens, five agents that induce E. coli heat shock genes were tested for their abilities to induce a P2-lacZ fusion in A. tumefaciens. P2 was most strongly induced by low pH, was moderately stimulated by CdCl2 or mitomycin C, and was slightly induced by P2 as measured by beta-galactosidase activity and primer extension analysis. Induction by these treatments did not require any Ti plasmid-encoded function or the chromosomally encoded RecA protein. We also pulse-labeled cellular proteins after a shift to low pH and detected several proteins whose synthesis was induced by these conditions. We conclude that P2 is primarily induced by acid pH and secondarily by certain other stimuli, each of which is stressful to cell growth. This stress induction is at least partly independent of the heat shock and SOS responses.
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DOI：
10.1073/pnas.82.9.2679
发表时间：
1985-01-01
影响因子：
11.1
作者：
COWING, DW;BARDWELL, JCA;GROSS, CA
通讯作者：
GROSS, CA
影响因子：
11.4
作者：
LEROUX, B;YANOFSKY, MF;NESTER, EW
通讯作者：
NESTER, EW
影响因子：
2.6
作者：
T. Close;D. Zaitlin;C. Kado
通讯作者：
T. Close;D. Zaitlin;C. Kado
农杆菌毒力所必需的基因与正调控基因座家族同源。
DOI：
10.1073/pnas.83.21.8278
发表时间：
1986
影响因子：
11.1
作者：
Winans,SC;Ebert,PR;Stachel,SE;Gordon,MP;Nester,EW
通讯作者：
Nester,EW
DOI：
10.1073/pnas.87.17.6708
发表时间：
1990-09-01
影响因子：
11.1
作者：
CANGELOSI, GA;ANKENBAUER, RG;NESTER, EW
通讯作者：
NESTER, EW