The interplay between iron, haem and manganese in Porphyromonas gingivalis

Abstract

a b s t r a c tBackground: Transition metals including iron and manganese are necessary for life because of their ability to donate and accept electrons. Approximately one-third of all proteins require essential transition metal ions to perform catalytic, structural and regulatory functions. These essential metal ions react differently to the presence of oxygen radicals with iron directly involved in the formation of toxic reactive oxygen species, whilst manganese can protect against oxidative stress. Highlight: Anaerobic bacterial species have been poorly studied with regard to transition metal homoeostasis and behave differently in many respects when compared with aerobic or aerotolerant species. To optimise catabolism whilst protecting themselves from unwanted reactions bacterial cells must maintain intracellular metal levels in a very narrow range that varies, dependent on the environment. To maintain metal ion homoeostasis, bacteria have evolved complex regulatory mechanisms of metal uptake, secretion and storage. In this review we examine how iron, haem and manganese availability dictate the lifestyle and virulence of the anaerobic Gram-negative, periodontal pathogen Porphyromonas gingivalis. Conclusion: P. gingivalis has novel haem, iron and manganese transporters and metalloregulatory proteins that enable it to switch rapidly between an energy efficient iron-dependent virulent phase and a protective manganese-dependent survival phase.

Outer Membrane Vesicle Proteome of Porphyromonas gingivalis Is Differentially Modulated Relative to the Outer Membrane in Response to Heme Availability

“…The importance of acquiring this essential micronutrient is highlighted by the number of heme acquisition systems identified in P. gingivalis to date. 23,25 Given the wellcharacterized comparative effects of heme-excess and hemelimited growth on virulence, gene expression, and the proteome of P. gingivalis, we used this bacterium as a model system to determine if specific environmental conditions can modulate the proteome of OMVs relative to the cell. A proteomics approach using label-free quantification (LFQ) with MaxQuant 26 was utilized to determine the changes in protein abundance in P. gingivalis W50 whole culture, cells, and OMVs grown in continuous culture between heme-limited and heme-excess conditions.…”

“…Heme-limited conditions to some extent mimic periodontically healthy tissues, where there is little to no bleeding, whereas heme-excess conditions mimic the disease state where damage to the microvasculature and consequent bleeding is common. The importance of acquiring this essential micronutrient is highlighted by the number of heme acquisition systems identified in P. gingivalis to date. , Given the well-characterized comparative effects of heme-excess and heme-limited growth on virulence, gene expression, and the proteome of P. gingivalis , we used this bacterium as a model system to determine if specific environmental conditions can modulate the proteome of OMVs relative to the cell.…”

Characterisation of the Porphyromonas gingivalis Manganese Transport Regulator Orthologue

“…Although iron is limited during colonization and disease quiescence, it becomes abundant during periodontal disease where tissue damage and bleeding are common, and P . gingivalis is exposed to oxidative stress from host cells [ 37 , 42 ].…”