Major nucleolar proteins shuttle between nucleus and cytoplasm.
Nucleolin is a 92 kd nucleolar protein implicated in regulating polymerase I transcription and binding of preribosomal RNA. Another abundant nucleolar protein of 38 kd ( B23/No38) is thought to be involved in intranuclear packaging of preribosomal particles. Although both proteins have previously been detected only in nuclei, we conclude that they shuttle constantly between nucleus and cytoplasm. This conclusion is based on monitoring the equilibration of these proteins between nuclei present in interspecies heterokaryons, and on observing the antigen-mediated nuclear accumulation of cytoplasmically injected antibodies. Our unexpected results suggest a role for these major nucleolar proteins in the nucleocytoplasmic transport of ribosomal components. Moreover, they suggest that transient exposure of shuttling proteins to the cytoplasm may provide a mechanism for cytoplasmic regulation of nuclear activities.[1]References
- Major nucleolar proteins shuttle between nucleus and cytoplasm. Borer, R.A., Lehner, C.F., Eppenberger, H.M., Nigg, E.A. Cell (1989) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
