The roles of RgpB and Kgp in late onset gingipain activity in the vimA‐defective mutant of Porphyromonas gingivalis W83. (8th May 2015)

• Record Type: Journal Article
• Authors: Dou, Y.; Robles, A.; Roy, F.; Aruni, A.W.; Sandberg, L.; Nothnagel, E.; Fletcher, H.M.
• Is Part Of: Molecular oral microbiology. Volume 30:Number 5(2015)
• Page Start: 347
• Page End: 360
• Publication Date: 2015-05-08
• Subjects: Mouth -- Microbiology -- Periodicals; Respiratory infections -- Microbiology -- Periodicals; Mouth -- Diseases -- Immunological aspects -- Periodicals; 617.522
• DOI: 10.1111/omi.12098
• Languages: English
• ISSNs: 2041-1006

Abstract

<abstract abstract-type="main" id="omi12098-abs-0001"> <title>Summary</title> <p>Previous studies have shown that VimA, an acetyltransferase, can modulate gingipain biogenesis in <italic>Porphyromonas gingivalis</italic>. Inactivation of the <italic>vimA</italic> gene resulted in isogenic mutants that showed a late onset of gingipain activity that only occurred during the stationary growth phase. To further elucidate the role and contribution of the gingipains in this VimA‐dependent process, isogenic mutants defective in the gingipain genes in the <italic>vimA</italic>‐deficient genetic background were evaluated. In contrast with the wild‐type strain, RgpB and Kgp gingipain activities were absent in exponential phase in the <italic>∆rgpA</italic>::<italic>tetQ</italic>‐<italic>vimA</italic>::<italic>ermF</italic> mutant. However, these activities increased to 31 and 53%, respectively, of that of the wild‐type during stationary phase. In the ∆<italic>rgpA</italic>::<italic>cat</italic>‐∆<italic>kgp</italic>::<italic>tetQ</italic>‐<italic>vimA</italic>::<italic>ermF</italic> mutant, the RgpB protein was observed in the extracellular fraction but no activity was present even at the stationary growth phase. There was no gingipain activity observed in the ∆<italic>rgpB</italic>::<italic>cat</italic>‐∆<italic>kgp</italic>::<italic>tetQ</italic>‐<italic>vimA</italic>::<italic>ermF</italic> mutant whereas Kgp activity in ∆<italic>rgpA</italic>::<italic>cat</italic>‐∆<italic>rgpB</italic>::<italic>tetQ</italic>‐<italic>vimA</italic>::<italic>ermF</italic> mutant was 24% of the wild‐type at late stationary phase. In contrast to RgpA, the glycosylation profile of the RgpB catalytic domain from both W83 and <italic>P. gingivalis </italic>FLL92 (<italic>vimA</italic>::<italic>ermF</italic>) showed similarity. Taken together, the results suggest multiple gingipain activation pathways in <italic>P. gingivalis</italic>. Whereas the maturation pathways for RgpA and RgpB are different, the late‐onset gingipain activity in the <italic>vimA</italic>‐defective mutant was due to activation/maturation of RgpB and Kgp. Moreover, unlike RgpA, which is VimA‐dependent, the maturation/activation pathways for RgpB and Kgp are interdependent in the absence VimA.</p> </abstract>