The rules and roles of nucleocytoplasmic shuttling proteins.
The spatial separation of mRNA synthesis from translation, while providing eukaryotes with the possibility to achieve higher complexity through a more elaborate regulation of gene expression, has set the need for transport mechanisms through the nuclear envelope. In a simplistic view of nucleocytoplasmic transport, nuclear proteins are imported into the nucleus while RNAs are exported to the cytoplasm. The reality is, however, that transport of either proteins or RNAs across the nuclear envelope can be bi-directional. During the past years, an increasing number of proteins have been identified that shuttle continuously back and forth between the nucleus and the cytoplasm. The emerging picture is that shuttling proteins are key factors in conveying information on nuclear and cytoplasmic activities within the cell.
Gama-Carvalho
M
M
Institute of Histology and Embryology, Faculty of Medicine, University of Lisbon, Av. Prof. Egas Moniz, 1649-028, Lisbon, Portugal.
Carmo-Fonseca
M
M
D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism*; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D020931:ran GTP-Binding Protein / Q000378:metabolism
D009687:Nuclear Proteins; D012333:RNA, Messenger; D020931:ran GTP-Binding Protein