ACTIVATION OF ALPHA-TOXIN TRANSLATION IN STAPHYLOCOCCUS-AUREUS BY THE TRANS-ENCODED ANTISENSE RNA, RNAIII
ACTIVATION OF ALPHA-TOXIN TRANSLATION IN STAPHYLOCOCCUS-AUREUS BY THE TRANS-ENCODED ANTISENSE RNA, RNAIII
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DOI：
10.1002/j.1460-2075.1995.tb00136.x
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发表时间：
1995-09-15
期刊：
影响因子：
11.4
通讯作者：
ARVIDSON, S
中科院分区：
文献类型：
--
作者：
MORFELDT, E;TAYLOR, D;ARVIDSON, S
金黄色葡萄球菌中毒力因子的合成由agr基因座编码的调节RNA分子RNAIII控制。编码分泌毒素和酶的基因的转录被刺激，而细胞表面蛋白基因的转录被RNAIII抑制。在葡萄球菌α毒素的情况下，RNAIII似乎也通过独立的机制刺激翻译。在这份报告中，我们表明，在一个突变体缺乏RNAIII的α-毒素（HLA）的生产率相对于HLA mRNA的细胞浓度相比，野生型菌株减少了10倍。RNAIII的5'端和hla转录物的5'非翻译区之间75%的互补性表明RNA之间的直接相互作用。从野生型菌株的总RNA提取物中证明了RNAIII和HLA mRNA的复合物，也与体外合成的RNA。核糖核酸酶T1消化实验表明，HLA转录本的核糖体结合位点被分子内碱基配对阻断。与RNAIII的杂交阻止了这种分子内碱基配对，并使hla mRNA可用于翻译起始。据我们所知，这是刺激靶mRNA翻译的“反义RNA”的第一个例子。
The synthesis of virulence factors in Staphylococcus aureus is controlled by a regulatory RNA molecule, RNAIII, encoded by the agr locus. Transcription of genes coding for secreted toxins and enzymes is stimulated, while transcription of cell-surface protein genes is repressed by RNAIII. In the case of staphylococcal alpha-toxin, RNAIII also seems to stimulate translation by an independent mechanism. In this report we show that in a mutant lacking RNAIII the rate of alpha-toxin (hla) production relative to the cellular concentration of hla mRNA was reduced 10-fold as compared with the wild-type strain. A 75% complementarity between the 5' end of RNAIII and the 5' untranslated region of the hla transcript suggests a direct interaction between the RNAs. A complex of RNAIII and hla mRNA was demonstrated in extracts of total RNA from the wild-type strain, and also with in vitro synthesized RNAs. Ribonuclease T1 digestion experiments revealed that the ribosome binding site of the hla transcript is blocked by intramolecular base-pairing. Hybridization with RNAIII prevents this intramolecular base-pairing and makes the hla mRNA accessible for translation initiation. This is, to our knowledge, the first example of an 'antisense RNA' that stimulates translation of the target mRNA.