Related Experiment Video
Updated: Aug 19, 2026

Assay to Measure Nucleocytoplasmic Transport in Real Time within Motor Neuron-like NSC-34 Cells
Published on: May 16, 2017
ATP depletion affects NPM translocation and exportation of rRNA from nuclei
1Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030, USA.
Abstract:
Nucleophosmin/B23 (NPM) is a nucleolar phosphoprotein which shifts from nucleoli to the nucleoplasm in cells treated with certain cytotoxic agents (NPM-translocation). NPM requires GTP for localization into nucleoli (J. Biol. Chem. 268, 5823-5827, 1993). To understand more about NPM's dynamic localization, the effects of lowering ATP on NPM-translocation and rRNA synthesis were studied. When the ATP level in HeLa cells was reduced by sodium azide, NPM-translocation was blocked. Similar results were obtained when ATP was depleted by other agents, suggesting that ATP depletion was responsible for the blocking of NPM-translocation. It was found that newly synthesized rRNA accumulated in the nuclei during ATP-depletion. Significantly larger than normal nucleoli were also observed. These results indicate that NPM may be involved in the transportation of newly synthesized ribosomes.
Related Concept Videos
Nuclear Export of mRNA
Regulated mRNA Transport
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...
Nuclear Export
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
Directionality of Nuclear Transport
Nuclear Export of mRNA

