Early-blocked sporulation mutations alter expression of enzymes under carbon control in Bacillus subtilis.
Early-blocked sporulation mutations alter expression of enzymes under carbon control in Bacillus subtilis.
复制标题
早期阻断的孢子形成突变改变了枯草芽孢杆菌中碳控制下的酶的表达。
DOI：
10.1007/bf00334696
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Price,CW
中科院分区：
文献类型：
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作者：
Boylan,SA;Chun,KT;Edson,BA;Price,CW
由早期阻断孢子形成突变 (spo0) 及其第二位点抑制等位基因 (rvtA11 和 crsA47) 定义的基因子集的生理作用对于营养和产孢枯草芽孢杆菌细胞来说仍然是神秘的。为了检验 spo0 基因产物影响全局调节的假设，我们测定了在含有各种碳和氮源的限定基本培养基中生长的野生型和 spo0 菌株中碳和氮敏感酶的水平。所有 spo0 突变（spo0J 除外）都以意想不到的方式影响组氨酸酶和阿拉伯糖异构酶水平：当细胞在去抑制碳源阿拉伯糖或麦芽糖上生长时，与野生型相比，spo0 菌株中两种碳敏感酶的水平高出两到六倍。葡萄糖生长的细胞的酶水平没有差异，碳独立酶谷氨酰胺合成酶和葡萄糖-6-磷酸脱氢酶的水平也没有显着差异。这种效应并不是由于所使用的贫乏碳源和氮源上spo0突变体的生长速度较慢所致。碳敏感酶的水平并不简单地与基因抑制的spo0突变体中的孢子形成能力相关，但ThervtA和crsA抑制剂各自对野生型生长和酶水平具有如此显着的影响，以至于这些结果难以解释。我们得出的结论是，直接或间接的孢子突变虽然阻断了孢子形成过程，但可能在基因表达水平上增加了碳敏感酶的水平。
The physiological roles of the gene subset defined by early-blocked sporulation mutations (spo0) and their second-site suppressor alleles (rvtA11andcrsA47) remain cryptic for both vegetative and sporulatingBacillus subtiliscells. To test the hypothesis thatspo0gene products affect global regulation, we assayed the levels of carbon- and nitrogen-sensitive enzymes in wild-type andspo0strains grown in a defined minimal medium containing various carbon and nitrogen sources. All thespo0mutations (exceptspo0J) affected both histidase and arabinose isomerase levels in an unexpected way: levels of both carbon-sensitive enzymes were two- to six-fold higher inspo0strains compared to wild type, when cells were grown on the derepressing carbon sources arabinose or maltose. There was no difference in enzyme levels with glucose-grown cells, nor was there a significant difference in levels of the carbonindependent enzymes glutamine synthetase and glucose-6-phosphate dehydrogenase. This effect was not due to a slower growth rate for thespo0mutants on the poor carbon and nitrogen sources used. The levels of carbon-sensitive enzymes were not simply correlated with sporulation ability in genetically suppressedspo0mutants, but thervtAandcrsAsuppressors each had such marked effects on wild-type growth and enzyme levels that these results were difficult to interpret. We conclude that directly or indirectly thespo0mutations, although blocking the sporulation process, increase levels of carbon-sensitive enzymes, possibly at the level of gene expression.