Neisseria prophage repressor implicated in gonococcal pathogenesis.

Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea, can infect and colonize multiple mucosal sites in both men and women. The ability to cope with different environmental conditions requires tight regulation of gene expression. In this study, we identified and characterized a gonococcal transcriptional regulatory protein (Neisseria phage repressor [Npr]) that was previously annotated as a putative gonococcal phage repressor protein. Npr was found to repress transcription of NGNG_00460 to NGNG_00463 (NGNG_00460-00463), an operon present within the phage locus NgoΦ4. Npr binding sites within the NGNG_00460-00463 promoter region were found to overlap the -10 and -35 promoter motifs. A gonococcal npr mutant demonstrated increased adherence to and invasion of human endocervical epithelial cells compared to a wild-type gonococcal strain. Likewise, the gonococcal npr mutant exhibited enhanced colonization in a gonococcal mouse model of mucosal infection. Analysis of the gonococcal npr mutant using RNA sequence (RNA-seq) analysis demonstrated that the Npr regulon is limited to the operon present within the phage locus. Collectively, our studies have defined a new gonococcal phage repressor protein that controls the transcription of genes implicated in gonococcal pathogenesis.