NLS copy-number variation governs efficiency of nuclear import - Case study on dUTPases

Gergely Róna, Hajnalka L. Pálinkás, Máté Borsos, András Horváth, Ildikó Scheer, András Benedek, Gergely N. Nagy, Imre Zagyva, Beáta G. Vértessy

Research output: Contribution to journalArticle

5 Citations (Scopus)


Nucleocytoplasmic trafficking of large macromolecules requires an active transport machinery. In many cases, this is initiated by binding of the nuclear localization signal (NLS) peptide of cargo proteins to importin-αmolecules. Fine orchestration of nucleocytoplasmic trafficking is of particularly high importance for proteins involved in maintenance of genome integrity, such as dUTPases, which are responsible for prevention of uracil incorporation into the genome. In most eukaryotes, dUTPases have two homotrimeric isoforms: one of these contains three NLSs and is present in the cell nucleus, while the other is located in the cytoplasm or the mitochondria. Here we focus on the unusual occurrence of a pseudo-heterotrimeric dUTPase in Drosophila virilis that contains one NLS, and investigate its localization pattern compared to the homotrimeric dUTPase isoforms of Drosophila melanogaster. Although the interaction of individual NLSs with importin-α has been well characterized, the question of how multiple NLSs of oligomeric cargo proteins affect their trafficking has been less frequently addressed in adequate detail. Using the D. virilis dUTPase as a fully relevant physiologically occurring model protein, we show that NLS copy number influences the efficiency of nuclear import in both insect and mammalian cell lines, as well as in D. melanogaster and D. virilis tissues. Biophysical data indicate that NLS copy number determines the stoichiometry of complexation between importin-α and dUTPases. The main conclusion of our study is that, in D. virilis, a single dUTPase isoform efficiently reproduces the cellular dUTPase distribution pattern that requires two isoforms in D. melanogaster.

Original languageEnglish
Pages (from-to)5463-5478
Number of pages16
JournalFEBS Journal
Issue number24
Publication statusPublished - Dec 2014



  • Importin
  • Nuclear localization signal
  • Nucleocytoplasmic trafficking
  • Oligomer proteins
  • Regulation
  • Stoichiometry
  • dUTPase

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Róna, G., Pálinkás, H. L., Borsos, M., Horváth, A., Scheer, I., Benedek, A., Nagy, G. N., Zagyva, I., & Vértessy, B. G. (2014). NLS copy-number variation governs efficiency of nuclear import - Case study on dUTPases. FEBS Journal, 281(24), 5463-5478.