title: Two epithelial cell invasion-related loci of the oral pathogen Actinobacillus actinomycetemcomitans.
abstract: Two invasion-related loci, apiA and the two-gene operon apiBC, were isolated from the oral pathogen Actinobacillus actinomycetemcomitans UT32. apiA encodes a 32.5 kDa protein that migrates on SDS-PAGE as a 101 kDa protein as detected by Western blot analysis or silver staining of an outer membrane-enriched fraction of Escherichia coli transformants. E. coli expressing ApiA have a different phenotype than the host vector, in broth and on solid media, and a colony morphology that resembles that of fresh A. actinomycetemcomitans isolates. These E. coli transformants bound to chicken collagen type II, human collagen type II, III, V and fibronectin. apiB and apiC encode proteins of 130.1 and 70.6 kDa, respectively. ApiBC conferred on E. coli a slightly enhanced ability to bind to collagen type III. ApiA- and ApiB-deficient mutants were constructed in A. actinomycetemcomitans. The ApiB-mutant had 4-fold diminished invasion of KB cells; the ApiA-mutant had increased invasion. Both loci were found in all A. actinomycetemcomitans strains, although polymorphism was detected only for apiBC. The deduced sequences of these invasion-related proteins are homologous to members of the YadA adhesin/invasin family.
authors.affiliation: University of Toronto, Faculty of Dentistry, Toronto, Ontario, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: D
authors.initials: D
authors.lastname: Matevski
authors.forename: M
authors.initials: M
authors.lastname: Aspiras
authors.forename: R P
authors.initials: RP
authors.lastname: Ellen
authors.forename: G
authors.initials: G
authors.lastname: Lépine
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics*; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D002645:Chickens; D002874:Chromosome Mapping; D024043:Collagen Type II / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D024062:Collagen Type V / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics; D009876:Operon / Q000235:genetics; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D014170:Transformation, Genetic / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D024043:Collagen Type II; D024061:Collagen Type III; D024062:Collagen Type V; D005353:Fibronectins; C064832:YadA protein, Yersinia; C053476:invasin, Yersinia