title: Por secretion system-dependent secretion and glycosylation of Porphyromonas gingivalis hemin-binding protein 35.
abstract: The anaerobic Gram-negative bacterium Porphyromonas gingivalis is a major pathogen in severe forms of periodontal disease and refractory periapical perodontitis. We have recently found that P. gingivalis has a novel secretion system named the Por secretion system (PorSS), which is responsible for secretion of major extracellular proteinases, Arg-gingipains (Rgps) and Lys-gingipain. These proteinases contain conserved C-terminal domains (CTDs) in their C-termini. Hemin-binding protein 35 (HBP35), which is one of the outer membrane proteins of P. gingivalis and contributes to its haem utilization, also contains a CTD, suggesting that HBP35 is translocated to the cell surface via the PorSS. In this study, immunoblot analysis of P. gingivalis mutants deficient in the PorSS or in the biosynthesis of anionic polysaccharide-lipopolysaccharide (A-LPS) revealed that HBP35 is translocated to the cell surface via the PorSS and is glycosylated with A-LPS. From deletion analysis with a GFP-CTD[HBP35] green fluorescent protein fusion, the C-terminal 22 amino acid residues of CTD[HBP35] were found to be required for cell surface translocation and glycosylation. The GFP-CTD fusion study also revealed that the CTDs of CPG70, peptidylarginine deiminase, P27 and RgpB play roles in PorSS-dependent translocation and glycosylation. However, CTD-region peptides were not found in samples of glycosylated HBP35 protein by peptide map fingerprinting analysis, and antibodies against CTD-regions peptides did not react with glycosylated HBP35 protein. These results suggest both that the CTD region functions as a recognition signal for the PorSS and that glycosylation of CTD proteins occurs after removal of the CTD region. Rabbits were used for making antisera against bacterial proteins in this study.
authors: Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors: Mikio
authors: M
authors: Shoji
authors: Keiko
authors: K
authors: Sato
authors: Hideharu
authors: H
authors: Yukitake
authors: Yoshio
authors: Y
authors: Kondo
authors: Yuka
authors: Y
authors: Narita
authors: Tomoko
authors: T
authors: Kadowaki
authors: Mariko
authors: M
authors: Naito
authors: Koji
authors: K
authors: Nakayama
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D004058:Diffusion / Q000187:drug effects; D006031:Glycosylation / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D000081062:Heme-Binding Proteins; D006420:Hemeproteins / Q000737:chemistry / Q000378:metabolism*; D015151:Immunoblotting; D008070:Lipopolysaccharides / Q000494:pharmacology; D008954:Models, Biological; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D010449:Peptide Mapping; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D000081062:Heme-Binding Proteins; D006420:Hemeproteins; D008070:Lipopolysaccharides; D050505:Mutant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins