title: A unique cysteine proteinase gene of pathogenic Entamoeba histolytica correlates with virulence.
abstract: Extracellular neutral cysteine proteinases are an important virulence factor of E. histolytica. Experimental evidence supporting its role in invasion includes the ability to degrade components of the extracellular matrix and activate complement by specifically cleaving C3. We had previously reported the isolation of fragments encoding cysteine proteinase genes from HM-1 (ACP1) and a nonpathogenic strain (REF291, ACP2) by PCR using consensus sequences based on conserved structural motifs of eukaryotic cysteine proteinases. Using similar techniques, we have now identified a third gene encoding a cysteine proteinase which is present in both pathogenic and nonpathogenic strains and have correlated cysteine proteinase specific-mRNA levels with enhanced proteolytic activity and cytopathic effect on a fibroblast cell monolayer, a quantitative assay of virulence.
authors.affiliation: Department of Pathology, University of California, San Diego.
authors.forename: S
authors.initials: S
authors.lastname: Reed
authors.forename: J
authors.initials: J
authors.lastname: Bouvier
authors.forename: K
authors.initials: K
authors.lastname: Hirata
authors.forename: X
authors.initials: X
authors.lastname: Que
authors.forename: A S
authors.initials: AS
authors.lastname: Pollack
authors.forename: J C
authors.initials: JC
authors.lastname: Engel
authors.forename: F
authors.initials: F
authors.lastname: Gillin
authors.forename: J H
authors.initials: JH
authors.lastname: McKerrow
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000502:physiology; D004748:Entamoeba histolytica / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D005347:Fibroblasts; D017125:Genes, Protozoan; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D016053:RNA, Protozoan / Q000032:analysis; D014774:Virulence / Q000235:genetics
chemical_list: D007527:Isoenzymes; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan; D003546:Cysteine Endopeptidases