Quantitative proteomic analysis of the type IX secretion system mutants in Porphyromonas gingivalis

AbstractPorphyromonas gingivalis is an anaerobic, Gram ‐negative human oral pathogen highly associated with chronic periodontitis.P. gingivalis utilises the type IX secretion system (T9SS) to transport many of its virulence factors including the gingipains to the cell surface. The T9SS is comprised of at least 16 proteins and the involvement of these 16 proteins in the T9SS has been verified by creating gene deletion mutants inP. gingivalis. These T9SS mutants are regularly utilised to understand how these proteins function together to allow the secretion of the T9SS substrates. We performed label ‐free quantitative proteomic analysis on the T9SS protein mutants inP. gingivalis to understand the relative abundance of each T9SS component in different mutants. The T9SS components were reduced in abundance in theporK, porL, porM, porN, sov andporT mutants while they were increased in theporE, porU, porV, porZ andporQ mutants. Sov and PorW appear to be the lowest in abundance and PorV the highest amongst all the T9SS components inP. gingivalis wild ‐type strain. These results are consistent with the proposed role of Sov as the translocation pore in the outer membrane and PorV as the shuttle protein that transports the T9SS substrates between sub‐complexes. Together, the label‐free quantitative proteomics analyses showed that different T9 SS mutants have vastly different abundances of the T9SS components. This knowledge will greatly assist in interpreting the phenoty...
Source: Molecular Oral Microbiology - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research