Novick R P, Ross H F, Projan S J, Kornblum J, Kreiswirth B, Moghazeh S
Department of Plasmid Biology, Public Health Research Institute, New York, NY 10016.
EMBO J. 1993 Oct;12(10):3967-75. doi: 10.1002/j.1460-2075.1993.tb06074.x.
The production of most toxins and other exoproteins in Staphylococcus aureus is controlled globally by a complex polycistronic regulatory locus, agr. Secretory proteins are up-regulated by agr whereas surface proteins are down-regulated. agr contains two divergent promoters, one of which directs the synthesis of a 514 nucleotide (nt) transcript, RNAIII. In this report, we show that the cloned RNAIII determinant restores both positive and negative regulatory functions of agr to an agr-null strain and that the RNA itself, rather than any protein, is the effector molecule. RNAIII acts primarily on the initiation of transcription and, secondarily in some cases, at the level of translation. In these cases, translation and transcription are regulated independently. RNAIII probably regulates translation directly by interacting with target gene transcripts and transcription indirectly by means of intermediary protein factors.
金黄色葡萄球菌中大多数毒素和其他外蛋白的产生受一个复杂的多顺反子调控位点agr的全局控制。分泌蛋白由agr上调，而表面蛋白则被下调。agr包含两个方向相反的启动子，其中一个指导合成一个514个核苷酸（nt）的转录本RNAIII。在本报告中，我们表明克隆的RNAIII决定簇可将agr的正负调控功能恢复到一个agr缺失菌株，并且RNA本身而非任何蛋白质是效应分子。RNAIII主要作用于转录起始，在某些情况下其次作用于翻译水平。在这些情况下，翻译和转录是独立调控的。RNAIII可能通过与靶基因转录本相互作用直接调节翻译，并通过中间蛋白因子间接调节转录。
