USE OF A REPORTER GENE TO FOLLOW HIGH-PRESSURE SIGNAL-TRANSDUCTION IN THE DEEP-SEA BACTERIUM PHOTOBACTERIUM SP STRAIN SS9
USE OF A REPORTER GENE TO FOLLOW HIGH-PRESSURE SIGNAL-TRANSDUCTION IN THE DEEP-SEA BACTERIUM PHOTOBACTERIUM SP STRAIN SS9
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DOI：
10.1128/jb.175.23.7533-7540.1993
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发表时间：
1993-12-01
影响因子：
3.2
通讯作者：
BARTLETT, DH
中科院分区：
文献类型：
--
作者：
CHI, E;BARTLETT, DH
发光杆菌菌株SS 9是一种深海细菌，其调节作为静水压力的函数的几种外膜蛋白的丰度。这些蛋白质包括先前克隆的ompH基因的产物（D. H. Bartlett，M. Wright，A. A. Yayanos和M.西尔弗曼Nature（伦敦）342：572-574，1989）。在接合质粒递送之后，有可能将ompH：：lacZ转录融合体杂交到SS 9的基因组中，替换野生型ompH基因，产生菌株EC 10。EC 10在高压下生长不受影响，表明在所采用的生长条件下，OmpH不需要压力适应。EC 10中β-半乳糖苷酶的产生被高压诱导至与亲本菌株SS 9中OmpH产生大致相同的程度。因此，OmpH丰度似乎主要在转录水平上调节。EC 10用于ompH调节突变体的分离。获得了EC 10的衍生物，其在低压和高压下均产生降低水平的β-半乳糖苷酶，并且似乎具有ompH：：lacZ基因座之外的突变。所有这些调节突变体显示的第二外膜蛋白，指定OmpL的高压抑制的改变，和两个突变体也缺乏高压诱导的第三外膜蛋白，指定OmpI。最引人注目的表型是在突变体EC 1002中，其生长是非常气压敏感的。EC 1002是迄今为止分离到的第一个压力敏感突变体。EC 1002在高压下长时间孵育导致具有野生型生长特征的细胞在高压下积累。这些细胞被认为具有抑制突变，因为它们仍然缺乏β-半乳糖苷酶的生产，并在没有高压选择的情况下保持其高压适应表型许多代。
Photobacterium sp. strain SS9 is a deep-sea bacterium which modulates the abundances of several outer membrane proteins as a function of hydrostatic pressure. These proteins include the product of the previously cloned ompH gene (D. H. Bartlett, M. Wright, A. A. Yayanos, and M. Silverman. Nature (London) 342:572-574, 1989). Subsequent to conjugal plasmid delivery it was possible to cross an ompH::lacZ transcriptional fusion into the genome of SS9, replacing the wild-type ompH gene, generating strain EC10. EC10 is not impaired in growth at high pressure, indicating that under the growth conditions employed, OmpH is not required for baroadaptation. beta-Galactosidase production in EC10 is induced by high pressure to approximately the same extent that OmpH production is in the parental strain, SS9. Therefore, OmpH abundance appears to be primarily regulated at the transcriptional level. EC10 was used for the isolation of ompH regulatory mutants. Derivatives of EC10 which produce reduced levels of beta-galactosidase at both low and high pressure and which appeared to possess mutations outside the ompH::lacZ locus were obtained. All of these regulatory mutants displayed alterations in the high-pressure repression of a second outer membrane protein, designated OmpL, and two of the mutants were also deficient in the high-pressure induction of a third outer membrane protein, designated OmpI. The most dramatic phenotype was present in mutant EC1002, whose growth was extremely barosensitive. EC1002 is the first pressure-sensitive mutant ever isolated. Prolonged incubation of EC1002 at high pressure led to the accumulation of cells with wild-type growth characteristics at high pressure. These cells are suggested to possess suppressor mutations, as they remain deficient in beta-galactosidase production and maintain their high-pressure-adapted phenotype for many generations in the absence of high-pressure selection.