Abstract |
The nuclear localization signal (NLS) of the DNA helicase involved in Werner's syndrome (WS) was studied. Previously, we noted that the C-terminal region of WS helicase contains the NLS. In this study, we generated in HeLa cells various chimeric proteins consisting of the N-terminal tagged with an enhanced green fluorescent protein and the C-terminal fragments of the WS helicase that were truncated either from N- or C-termini, and we examined the ability of fragments to transfer the fusion proteins to the nucleoplasm by fluorescence microscopy. A small C-proximal region containing 34 amino acid residues (residues 1369-1402) was found to contain full nuclear migration activities. Subsequent amino acid substitution experiments showed that a sequence of three positively charged amino acids (Lys1371-Arg1372-Arg1373) in this region are particularly important. Similar sequence has previously been defined as the nuclear localization signal of SV-40 large T antigen that also acts as a viral DNA helicase. Conservation of this motif was found in the C-terminal regions of the other RecQ type DNA helicases, including murine WS helicase, yeast sgs1 and rqh+1 and human Bloom syndrome DNA helicases.
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Authors | T Matsumoto, O Imamura, M Goto, Y Furuichi |
Journal | International journal of molecular medicine
(Int J Mol Med)
Vol. 1
Issue 1
Pg. 71-6
(Jan 1998)
ISSN: 1107-3756 [Print] Greece |
PMID | 9852201
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Nuclear Localization Signals
- Adenosine Triphosphatases
- RECQL protein, human
- DNA Helicases
- RecQ Helicases
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Topics |
- Adenosine Triphosphatases
- Amino Acid Substitution
- Animals
- Cell Nucleus
- DNA Helicases
(chemistry, genetics, metabolism)
- HeLa Cells
- Humans
- Mice
- Nuclear Localization Signals
(genetics)
- Rats
- RecQ Helicases
- Werner Syndrome
(enzymology)
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