Role of the RprY response regulator in P. gingivalis community development and virulence

Abstract

Porphyromonas gingivalis, a keystone pathogen in periodontitis (Hajishengallis et al., 2012; Lamont et al., 2018), is an endogenous inhabitant of the oral cavity, in particular the subgingival space. This region is a complex and dynamic microhabitat containing a multispecies microbial community with a fluid phase of gingival crevicular fluid (Lamont et al., 2018). Bacterial adaptation to environmental cues is often mediated by two-component signal transduction systems (TCS) in which, canonically, a transmembrane sensor histidine kinase (HK) phosphorylates and activates a DNA-binding response regulator (RR). Variations on this theme include hybrid systems in which the HK and RR are in the same molecule, and orphan systems in which the RR lacks a cognate HK (Miller & Lamont, 2019; Stock et al., 2000). Recently, it has become apparent that bacterial serine/threonine and tyrosine kinases can overlay cross-phosphorylation interactions on signal

Identification and characterization of a UbK family kinase in Porphyromonas gingivalis that phosphorylates the RprY response regulator

“…Recently, we reported that the RprY orphan RR is tyrosine phosphorylated; however, RprY was not a substrate of the then only reported tyrosine kinase in P. gingivalis , Ptk1 (Shen et al., 2020). Hence, we tested RprY as a substrate for UbK1 using a 32 P assay, and found that UbK1 can phosphorylate RprY (Figure 2a).…”

“…Recently, we identified tyrosine phosphorylation of RprY on Y41 (Shen et al., 2020). Because UbK1 phosphorylated RprY, we investigated the impact of a RprY Y41 point mutation.…”

“…To generate substitutions in UbK1, the Q5 Site‐Directed Mutagenesis Kit (New England Biolabs, Ipswich, MA) was used with the primers listed in Table S1. RprY and mutant derivatives were purified as described previously (Shen et al., 2020).…”

“…The P. gingivalis genome contains relatively few TCSs, one of which is the orphan response regulator (RR) RprY (Krishnan & Duncan, 2013). RprY can also control heterotypic community development, and we recently established that it is tyrosine phosphorylated, although Ptk1 is not the cognate kinase (Shen et al., 2020). The question thus arose as to the nature of the phosphorylation of RprY.…”

Contribution of N ε -lysine Acetylation towards Regulation of Bacterial Pathogenesis

“…RprY regulates the expression of the type IX secretion system (T9SS), which exports many virulence factors. In support of this, RprY is required for virulence in a murine model ( 78 ). Thus, inhibition of RprY DNA-binding by acetylation is a mechanism to directly control secretion of virulence factors.…”