Related Experiment Video
Updated: May 24, 2026

Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria
Published on: January 7, 2022
Nuclear transport of Wilms' tumour protein Wt1 involves importins α and β
Reinhard Depping1, Susann G Schindler, Charlotte Jacobi
1Institut für Physiologie, Zentrum für Medizinische Struktur- und Zellbiologie, Universität zu Lübeck, Lübeck, Germany.
Background/Aims:
Wilms' tumour protein, Wt1, is a zinc finger molecule, which is required for normal embryonic development. Mutations of the WT1 gene can give rise to childhood cancer of the kidneys. Different Wt1 isoforms exist, which function either as transcription factors or have a presumed role in mRNA processing. Previous studies suggested that Wt1 undergoes nucleocytoplasmic shuttling, and cytoplasmic Wt1 was higher in malignant than in normal cells. The aim of this study was to analyse the molecular pathways along which Wt1 shuttles between the cytoplasm and nucleus.
Methods:
Interaction of Wt1 protein with various importin α subtypes and importin β was assessed in pull-down assays and co-immunoprecipitation experiments. Nuclear localisation signals (NLS) were identified by combining site-directed mutagenesis with subcellular immunodetection of the transfected Wt1 variants.
Results:
Wt1(+/-KTS) proteins were found to interact with importin α1 and importin β in vitro and in living cells in vivo. A NLS that was necessary and sufficient for nuclear import could be mapped to the third Wt1 zinc finger. Mutation of this NLS strongly weakened binding of Wt1 to importins.
Conclusion:
Nuclear translocation of Wilms' tumour protein involves importins α and β, and a NLS in the third zinc finger.
More Related Videos
Related Concept Videos
Nuclear Localization Signals and Import
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Mitochondrial Protein Sorting
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Directionality of Nuclear Transport
Regulation of Nuclear Protein Sorting
Nuclear Export
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
