title: Functional characterization of Caenorhabditis elegans DNA topoisomerase IIIalpha.
abstract: To investigate the function of a DNA topoisomerase III enzyme in Caenorhabditis elegans, the full-length cDNA of C.elegans DNA topoisomerase IIIalpha was cloned. The deduced amino acid sequence exhibited identities of 48 and 39% with those of human DNA topoisomerase IIIalpha and Saccharomyces cerevisiae DNA topoisomerase III, respectively. The overexpressed polypeptide showed an optimal activity for removing negative DNA supercoils at a relatively high temperature of 52-57 degrees C, which is similar to the optimum temperatures of other eukaryotic DNA topoisomerase III enzymes. When topoisomerase IIIalpha expression was interfered with by a cognate double-stranded RNA injection, pleiotropic phenotypes with abnormalities in germ cell proliferation, oogenesis and embryo-genesis appeared. These phenotypes were well correlated with mRNA expression localized in the meiotic cells of gonad and early embryonic cells.
authors.affiliation: Department of Biochemistry, College of Science, Yonsei University, Seoul, Korea.
authors.forename: Y C
authors.initials: YC
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: H S
authors.initials: HS
authors.lastname: Koo
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000201:enzymology / Q000235:genetics*; D002384:Catalysis; D003001:Cloning, Molecular; D004264:DNA Topoisomerases, Type I / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005796:Genes / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D016372:RNA, Antisense / Q000008:administration & dosage / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D059004:Topoisomerase I Inhibitors
chemical_list: D018076:DNA, Complementary; D016372:RNA, Antisense; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D059004:Topoisomerase I Inhibitors; D005982:Glutathione Transferase; D004264:DNA Topoisomerases, Type I