title: One of three nuclear localization signals of maize Activator (Ac) transposase overlaps the DNA-binding domain.
abstract: The nuclear localization sequences (NLSs) of the Ac transposase (TPase) protein have been characterized by indirect immunofluorescence detection of TPase deletion derivatives and TPase/beta-glucuronidase (GUS) fusion proteins in transiently transfected Petunia cells. The TPase contains three NLSs near its amino-terminal end, NLS(44-62), NLS(159-178) and NLS(174-206), each of which is sufficient to redirect GUS to the nucleus. Deletion of the N-terminal 102 TPase residues including NLS(44-62) results in strongly reduced nuclear import of the truncated TPase. NLS(44-62) and NLS(159-178) are bipartite NLSs, whereas the structure of NLS(174-206) does not allow a classification into one of the three major NLS categories. NLS(174-206) overlaps with the basic DNA-binding domain of TPase. A substitution of two amino acids in this segment (His191-->Arg and Arg193-->His) results in a total loss of DNA-binding activity, but retains reduced NLS activity. Accordingly, the two functions can be separated. In addition, we show that a NLS-deficient 71 kDa TPase derivative is co-imported into the nucleus in the presence of wild-type TPase.
authors.affiliation: Institut für Genetik, Universität zu Köln, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Boehm
authors.forename: M
authors.initials: M
authors.lastname: Heinlein
authors.forename: U
authors.initials: U
authors.lastname: Behrens
authors.forename: R
authors.initials: R
authors.lastname: Kunze
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000235:genetics; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D021382:Protein Sorting Signals / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D019895:Transposases; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D009713:Nucleotidyltransferases; D019895:Transposases; D005966:Glucuronidase