IADR Abstract Archives
The Porphyromonas Gingivalis RNA-Binding Protein is Required for Survival With Metal Stress, Protease Activity and Persistence With Host Cells
Objectives: The oral periodontal pathogen Porphyromonas gingivalis must adapt to ever
changing environment to survive and cause disease. So far most of the efforts
concerning the regulatory mechanisms employed by the bacterium centered on DNA-
binding regulators. Although global regulatory mechanisms employing RNA-binding
proteins (RBP) are reported in most forms of life so far, such mechanism of regulation
remains unknown in the oral Bacteroidetes group. Examination of the genome of P.
gingivalis led to discovery of a putative RBP with the RNA Recognition Motif 1 (RRM -1)
designated here RbpPg1 (RNA Binding Protein Porphyromonas gingivalis 1). The objective of this work was to characterize the protein.
Methods: We used RNA binding assays, RNA pull down assay, RNAseq, proteomics, protease assays, bacterial growth studies, host-pathogen interactions studies with variety of host cells.
Results: Recombinant form of the protein bound RNA and RNA-pull down identified a zinc
exporter transcript as the most enriched one in agreement with the higher levels of zinc
in the absence of the protein. Deletion of RbpPg1 reduced the ability of the bacterium to
grow with 0.5mM zinc. The RgpB protein level and the ArgX protease activity, was
reduced in both, iron replete and iron deplete conditions in the mutant strain when
compared to the wild type. Also, the Lys-X protease activity was reduced although the
protein levels were not altered by deletion of the RbpPg1. The mutant grew better in
hemin deplete conditions when compared to the wild type. Finally, RbpPg1 was
indispensable for the bacterium to survive with host cells. We have determined both the
transcriptome and proteome affected by deletion of RbpPg1 and found that the major
group of proteins with elevated expression were ones associated with response to
environmental stress changes while proteins mediating metabolic processes were
downregulated.
Conclusions: Overall, the first RBP characterized in P. gingivalis plays significant role
in biology of the bacterium and differs from RBPs in other Gram-negative bacteria.
changing environment to survive and cause disease. So far most of the efforts
concerning the regulatory mechanisms employed by the bacterium centered on DNA-
binding regulators. Although global regulatory mechanisms employing RNA-binding
proteins (RBP) are reported in most forms of life so far, such mechanism of regulation
remains unknown in the oral Bacteroidetes group. Examination of the genome of P.
gingivalis led to discovery of a putative RBP with the RNA Recognition Motif 1 (RRM -1)
designated here RbpPg1 (RNA Binding Protein Porphyromonas gingivalis 1). The objective of this work was to characterize the protein.
Methods: We used RNA binding assays, RNA pull down assay, RNAseq, proteomics, protease assays, bacterial growth studies, host-pathogen interactions studies with variety of host cells.
Results: Recombinant form of the protein bound RNA and RNA-pull down identified a zinc
exporter transcript as the most enriched one in agreement with the higher levels of zinc
in the absence of the protein. Deletion of RbpPg1 reduced the ability of the bacterium to
grow with 0.5mM zinc. The RgpB protein level and the ArgX protease activity, was
reduced in both, iron replete and iron deplete conditions in the mutant strain when
compared to the wild type. Also, the Lys-X protease activity was reduced although the
protein levels were not altered by deletion of the RbpPg1. The mutant grew better in
hemin deplete conditions when compared to the wild type. Finally, RbpPg1 was
indispensable for the bacterium to survive with host cells. We have determined both the
transcriptome and proteome affected by deletion of RbpPg1 and found that the major
group of proteins with elevated expression were ones associated with response to
environmental stress changes while proteins mediating metabolic processes were
downregulated.
Conclusions: Overall, the first RBP characterized in P. gingivalis plays significant role
in biology of the bacterium and differs from RBPs in other Gram-negative bacteria.