Takata R, Mukai T, Hori K
Department of Biology, Saga Medical School, Japan.
Mol Gen Genet. 1987 Aug;209(1):28-32. doi: 10.1007/BF00329832.
The synthesis of Escherichia coli polynucleotide phosphorylase (PNPase) was examined in a mutant strain defective in the RNA processing enzyme RNase III (Rnc-). We found that the specific activity and the synthesis rate of PNPase were increased in the Rnc- strain by more than three times that in an Rnc+ strain. Such increased synthesis of PNPase was not observed in a mutant strain transformed with a plasmid carrying the rnc+ gene. Quantitative analysis of RNA showed that the transcripts from the pnp gene, which encodes PNPase, were degraded more slowly in the Rnc- strain than in the Rnc+ strain. These results indicate that processing of the transcripts by RNase III is intimately involved in controlling the expression of pnp by affecting the stability of its messenger RNA.
在一种RNA加工酶核糖核酸酶III（Rnc-）缺陷的突变菌株中，对大肠杆菌多核苷酸磷酸化酶（PNPase）的合成进行了检测。我们发现，Rnc-菌株中PNPase的比活性和合成速率比Rnc+菌株中增加了三倍多。在用携带rnc+基因的质粒转化的突变菌株中未观察到PNPase的这种合成增加。RNA的定量分析表明，编码PNPase的pnp基因的转录本在Rnc-菌株中比在Rnc+菌株中降解得更慢。这些结果表明，核糖核酸酶III对转录本的加工通过影响其信使RNA的稳定性，密切参与了对pnp表达的控制。
