Borrelia burgdorferi encodes a functional homolog of canonical Lon protease termed Lon-2. To date, the contribution of Lon-2 to B. burgdorferi fitness and infection remains unexplored. Herein, we showed that expression of lon-2 was highly induced during animal infection, suggesting that Lon-2 is important for B. burgdorferi infection. We further generated a lon-2 deletion mutant. Compared with that of wild-type (WT) strain, the infectivity of the mutant was severely attenuated in a murine infection model. Although no growth defect was observed for the mutant in normal BSK-II medium, resistance of the lon-2 mutant to osmotic stress was markedly reduced. In addition, when exposed to tert-Butyl hydroperoxide, survival of the lon-2 mutant was impaired. In addition, we found that the protein levels of RpoS and RpoS-dependent OspC were decreased in the mutant. All these phenotypes were restored to WT or near-WT levels when lon-2 mutation was complemented in cis. Taken together, these results demonstrate that Lon-2 is critical for B. burgdorferi to establish infection and to cope with environmental stresses. This study provides a foundation for further uncovering the direct link between the dual roles of Lon-2 in protein quality control and bacterial pathogenesis.
|Original language||English (US)|
|Number of pages||13|
|State||Published - May 1 2020|
- Borrelia burgdorferi
- Lyme disease
ASJC Scopus subject areas
- Molecular Biology