title: Induction of the iron-containing superoxide dismutase in Entamoeba histolytica by a superoxide anion-generating system or by iron chelation.
abstract: The regulation of superoxide dismutase (SOD) expression was studied in 4 Entamoeba histolytica isolates. In comparison to anaerobic conditions, cultivation of the amoebae in the presence of superoxide radical anions or a ferrous iron chelator revealed substantial increase of SOD expression. Under the different culture conditions, all SOD activity could be exclusively attributed to an iron-containing type (FeSOD). Northern blot analysis revealed that FeSOD expression was regulated on the transcriptional level. Within the 5'-flanking region of the amoebic FeSOD gene, a 19-bp fragment was found with 68% sequence identity to the consensus motif of the binding site for the ferric uptake regulation gene product of Escherichia coli. Electrophoretic mobility shift assays with this 19-bp fragment and with amoebic nuclear extracts revealed specific DNA/protein complex formation. The results indicate that the regulation of E. histolytica FeSOD expression is similar to that of the manganese-containing SOD (MnSOD) of E. coli.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Bruchhaus
authors.forename: E
authors.initials: E
authors.lastname: Tannich
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D017931:DNA Primers / Q000737:chemistry; D004748:Entamoeba histolytica / Q000187:drug effects / Q000201:enzymology*; D004790:Enzyme Induction; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000494:pharmacology*; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D013482:Superoxide Dismutase / Q000096:biosynthesis* / Q000235:genetics; D013481:Superoxides / Q000494:pharmacology*
chemical_list: D017931:DNA Primers; D007502:Iron Chelating Agents; D013481:Superoxides; D007501:Iron; D013482:Superoxide Dismutase