Antisense regulation of Opa expression in Neisseria gonorrhoeae

性传播的人类病原体淋病奈瑟氏菌编码一个由11个外膜蛋白组成的家族，命名为OpA，它有助于黏附和入侵宿主细胞。由于在各自基因的5-末端存在五聚体序列重复，导致淋球菌种群的成员表达不同的OpA蛋白组合或根本不表达OpA蛋白，OPA的表达受阶段变化的影响。OPA蛋白被认为在发病机制中发挥了重要作用，因为从人类感染中分离出来的菌株主要是OpA阳性。最近通过RNA测序对淋球菌进行的转录组分析显示，OPA基因座存在大量反义转录。基于先前观察到的框架外OPA基因的全长转录本在细胞中几乎检测不到，我们假设OPA反义转录正在限制框架外OPA基因mRNAs的浪费积累和表达。在本提案中，我们讨论了OPA反义RNA在OPA表达控制中的作用，并研究了潜在的调控机制。

The sexually transmitted human pathogen Neisseria gonorrhoeae encodes a family of eleven outer membrane proteins named Opa which contribute to the adhesion to and invasion into host cells. Opa expression is subject to phase variation due to the presence of pentameric sequence repeats at the 5-end of the respective genes resulting in gonococcal populations whose members express different combinations of Opa proteins or no Opa proteins at all. Opa proteins are believed to play an important role in pathogenesis since isolates from human infection are predominantly Opa-positive. A recent transcriptome analysis of N. gonorrhoeae via RNA sequencing revealed massive antisense transcription from the opa gene loci. Based on the previous observation that full-length transcripts from out-of-frame opa genes are barely detectable in the cell we hypothesize that opa antisense transcription is limiting the wasteful accumulation and expression of out-of-frame opa mRNAs. In the present proposal we address the role of opa antisense RNAs in opa expression control and investigate the underlying regulatory mechanisms.