In:
The FEBS Journal, Wiley, Vol. 281, No. 24 ( 2014-12), p. 5463-5478
Abstract:
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‐α molecules. Fine orchestration of nucleocytoplasmic trafficking is of particularly high importance for proteins involved in maintenance of genome integrity, such as d UTP ases, which are responsible for prevention of uracil incorporation into the genome. In most eukaryotes, d UTP ases have two homotrimeric isoforms: one of these contains three NLS s 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 d UTP ase in Drosophila virilis that contains one NLS , and investigate its localization pattern compared to the homotrimeric d UTP ase isoforms of Drosophila melanogaster . Although the interaction of individual NLS s with importin‐α has been well characterized, the question of how multiple NLS s of oligomeric cargo proteins affect their trafficking has been less frequently addressed in adequate detail. Using the D. virilis d UTP ase 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 d UTP ases. The main conclusion of our study is that, in D. virilis , a single d UTP ase isoform efficiently reproduces the cellular d UTP ase distribution pattern that requires two isoforms in D. melanogaster . Structured digital abstract • ABC dUTPase and importin-a bind by molecular sieving ( View interaction ) • AAA dUTPase and importin-a bind by molecular sieving ( View interaction ) • ABC dUTPase and importin-a bind by comigration in non denaturing gel electrophoresis ( View interaction ) • AAA dUTPase and importin-a bind by comigration in non denaturing gel electrophoresis ( View interaction ) • ABC dUTPase and importin-a bind by isothermal titration calorimetry ( View interaction ) & #x2022; AAA dUTPase and importin-a bind by isothermal titration calorimetry ( View interaction )
Type of Medium:
Online Resource
ISSN:
1742-464X
,
1742-4658
DOI:
10.1111/febs.2014.281.issue-24
Language:
English
Publisher:
Wiley
Publication Date:
2014
detail.hit.zdb_id:
2172518-4
SSG:
12
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