Inactivation of vimF, a putative glycosyltransferase gene downstream of vimE, alters glycosylation and activation of the gingipains in Porphyromonas gingivalis W83.
Regulation/activation of the Porphyromonas gingivalis gingipains is poorly understood. A 1.2-kb open reading frame, a putative glycosyltransferase, downstream of vimE, was cloned, insertionally inactivated using the ermF-ermAM antibiotic resistance cassette, and used to create a defective mutant by allelic exchange. In contrast to the wild-type W83 strain, this mutant, designated P. gingivalis FLL95, was nonpigmented and nonhemolytic when plated on Brucella blood agar. Arginine- and lysine-specific gingipain activities were reduced by approximately 97% and 96%, respectively, relative to that of the parent strain. These activities were unaffected by the growth phase, in contrast to the vimA-defective mutant P. gingivalis FLL92. Expression of the rgpA, rgpB, and kgp gingipain genes was unaffected in P. gingivalis FLL95 in comparison to the wild-type strain. In nonactive gingipain extracellular protein fractions, multiple high-molecular-weight proteins immunoreacted with gingipain-specific antibodies. The specific gingipain-associated sugar moiety recognized by monoclonal antibody 1B5 was absent in FLL95. Taken together, these results suggest that the vimE downstream gene, designated vimF (virulence modulating gene F), which is a putative glycosyltransferase group 1, is involved in the regulation of the major virulence factors of P. gingivalis.
Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA. eguiness02x@som.llu.edu
Elaine
E
Vanterpool
Francis
F
Roy
Hansel M
HM
Fletcher
D018829:Adhesins, Bacterial; D000483:Alleles; D019295:Computational Biology; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004789:Enzyme Activation; D005353:Fibronectins / Q000378:metabolism; D000080867:Gingipain Cysteine Endopeptidases; D006031:Glycosylation; D016695:Glycosyltransferases / Q000235:genetics*; D006384:Hemagglutination; D006388:Hemagglutinins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000378:metabolism / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics*
D018829:Adhesins, Bacterial; D005353:Fibronectins; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; D037521:Virulence Factors; D016695:Glycosyltransferases; D003546:Cysteine Endopeptidases