Related Experiment Video
Updated: Jun 28, 2026

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)
Published on: June 10, 2020
Nucleocytoplasmic traffic of CPEB1 and accumulation in Crm1 nucleolar bodies
Michèle Ernoult-Lange1, Ania Wilczynska, Maryannick Harper
1CNRS, Institut André Lwoff, Villejuif Cedex, France.
Abstract:
The translational regulator CPEB1 plays a major role in the control of maternal mRNA in oocytes, as well as of subsynaptic mRNAs in neurons. Although mainly cytoplasmic, we found that CPEB1 protein is continuously shuttling between nucleus and cytoplasm. Its export is controlled by two redundant NES motifs dependent on the nuclear export receptor Crm1. In the nucleus, CPEB1 accumulates in a few foci most often associated with nucleoli. These foci are different from previously identified nuclear bodies. They contain Crm1 and were called Crm1 nucleolar bodies (CNoBs). CNoBs depend on RNA polymerase I activity, indicating a role in ribosome biogenesis. However, although they form in the nucleolus, they never migrate to the nuclear envelope, precluding a role as a mediator for ribosome export. They could rather constitute a platform providing factors for ribosome assembly or export. The behavior of CPEB1 in CNoBs raises the possibility that it is involved in ribosome biogenesis.
Related Concept Videos
Nuclear Export
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
Regulation of Nuclear Protein Sorting
Vesicular Tubular Clusters
With the help of motor proteins such...
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...
ER Retrieval Pathway
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
Nuclear Export of mRNA

