RNP export is mediated by structural reorganization of the nuclear pore basket.
Affiliation
CRC Department of Structural Cell Biology, Paterson Institute for Cancer Research, Christie Hospital, National Health Service Trust, Manchester, UK.Issue Date
1996-07-19
Metadata
Show full item recordAbstract
Messenger RNA leaves the cell nucleus as ribonucleoprotein (RNP) particles. The nucleocytoplasmic translocation of the particles takes place through the nuclear pore complex (NPC) and includes two steps: binding to the NPC and transit through its central channel. The NPC basket is a fishtrap-like component of NPC facing the nucleoplasm. Its position in the NPC strongly suggests that it has an important role in the initial steps of macromolecular export from the nucleus. Here we report a cyclic rearrangement of the basket structure in relation to the translocation of a specific messenger RNP (mRNP) of exceptional size, the Balbiani ring RNP particles in the salivary gland cells in Chironomus. We used field emission in-lens scanning electron microscopy (FEISEM), transmission electron microscopy (TEM), and immunocytochemistry to analyse the structural organization of the basket during the mRNP export. Our observations reveal five configurations of the basket which are presented in a model of basket reorganization related to the state of mRNP penetration into the NPC. We suggest that the functional role of the basket is to anchor the mRNP particle to the NPC and position it in correct orientation at the entrance to the central channel of the NPC.Citation
RNP export is mediated by structural reorganization of the nuclear pore basket. 1996, 260 (3):304-11 J. Mol. Biol.Journal
Journal of Molecular BiologyDOI
10.1006/jmbi.1996.0401PubMed ID
8757794Type
ArticleLanguage
enISSN
0022-2836ae974a485f413a2113503eed53cd6c53
10.1006/jmbi.1996.0401