Dimples, pores, star-rings, and thin rings on growing nuclear envelopes: evidence for structural intermediates in nuclear pore complex assembly.

2.50
Hdl Handle:
http://hdl.handle.net/10541/95499
Title:
Dimples, pores, star-rings, and thin rings on growing nuclear envelopes: evidence for structural intermediates in nuclear pore complex assembly.
Authors:
Goldberg, Martin W; Wiese, C; Allen, Terence D; Wilson, Katherine L
Abstract:
We used field emission in-lens scanning electron microscopy to examine newly-assembled, growing nuclear envelopes in Xenopus egg extracts. Scattered among nuclear pore complexes were rare 'dimples' (outer membrane depressions, 5-35 nm diameter), more abundant holes (pores) with a variety of edge geometries (35-45 nm diameter; 3.3% of structures), pores containing one to eight triangular 'star-ring' subunits (2.1% of total), and more complicated structures. Neither mature complexes, nor these novel structures, formed when wheat germ agglutinin (which binds O-glycosylated nucleoporins) was added at high concentrations (>500 microg/ml) directly to the assembly reaction; low concentrations (10 microg/ml) had no effect. However at intermediate concentrations (50-100 microg/ml), wheat germ agglutinin caused a dramatic, sugar-reversible accumulation of 'empty' pores, and other structures; this effect correlated with the lectin-induced precipitation of a variable proportion of each major Xenopus wheat-germ-agglutinin-binding nucleoporin. Another inhibitor, dibromo-BAPTA (5,5'-dibromo-1,2-bis[o-aminophenoxylethane-N,N,N',N'-tetraacetic acid), had different effects depending on its time of addition to the assembly reaction. When 1 mM dibromo-BAPTA was added at time zero, no pore-related structures formed. However, when dibromo-BAPTA was added to growing nuclei 40-45 minutes after initiating assembly, star-rings and other structures accumulated, suggesting that dibromo-BAPTA can inhibit multiple stages in pore complex assembly. We propose that assembly begins with the formation and stabilization of a hole (pore) through the nuclear envelope, and that dimples, pores, star-rings, and thin rings are structural intermediates in nuclear pore complex assembly.
Affiliation:
CRC Department of Structural Cell Biology, Paterson Institute for Cancer Research, Christie Hospital National Health Service Trust, Manchester, UK.
Citation:
Dimples, pores, star-rings, and thin rings on growing nuclear envelopes: evidence for structural intermediates in nuclear pore complex assembly. 1997, 110 ( Pt 4):409-20 J. Cell. Sci.
Journal:
Journal of Cell Science
Issue Date:
Feb-1997
URI:
http://hdl.handle.net/10541/95499
PubMed ID:
9067593
Type:
Article
Language:
en
ISSN:
0021-9533
Appears in Collections:
All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorGoldberg, Martin Wen
dc.contributor.authorWiese, Cen
dc.contributor.authorAllen, Terence Den
dc.contributor.authorWilson, Katherine Len
dc.date.accessioned2010-04-01T13:59:31Z-
dc.date.available2010-04-01T13:59:31Z-
dc.date.issued1997-02-
dc.identifier.citationDimples, pores, star-rings, and thin rings on growing nuclear envelopes: evidence for structural intermediates in nuclear pore complex assembly. 1997, 110 ( Pt 4):409-20 J. Cell. Sci.en
dc.identifier.issn0021-9533-
dc.identifier.pmid9067593-
dc.identifier.urihttp://hdl.handle.net/10541/95499-
dc.description.abstractWe used field emission in-lens scanning electron microscopy to examine newly-assembled, growing nuclear envelopes in Xenopus egg extracts. Scattered among nuclear pore complexes were rare 'dimples' (outer membrane depressions, 5-35 nm diameter), more abundant holes (pores) with a variety of edge geometries (35-45 nm diameter; 3.3% of structures), pores containing one to eight triangular 'star-ring' subunits (2.1% of total), and more complicated structures. Neither mature complexes, nor these novel structures, formed when wheat germ agglutinin (which binds O-glycosylated nucleoporins) was added at high concentrations (>500 microg/ml) directly to the assembly reaction; low concentrations (10 microg/ml) had no effect. However at intermediate concentrations (50-100 microg/ml), wheat germ agglutinin caused a dramatic, sugar-reversible accumulation of 'empty' pores, and other structures; this effect correlated with the lectin-induced precipitation of a variable proportion of each major Xenopus wheat-germ-agglutinin-binding nucleoporin. Another inhibitor, dibromo-BAPTA (5,5'-dibromo-1,2-bis[o-aminophenoxylethane-N,N,N',N'-tetraacetic acid), had different effects depending on its time of addition to the assembly reaction. When 1 mM dibromo-BAPTA was added at time zero, no pore-related structures formed. However, when dibromo-BAPTA was added to growing nuclei 40-45 minutes after initiating assembly, star-rings and other structures accumulated, suggesting that dibromo-BAPTA can inhibit multiple stages in pore complex assembly. We propose that assembly begins with the formation and stabilization of a hole (pore) through the nuclear envelope, and that dimples, pores, star-rings, and thin rings are structural intermediates in nuclear pore complex assembly.en
dc.language.isoenen
dc.subject.meshAnimals-
dc.subject.meshCell Division-
dc.subject.meshCell Membrane-
dc.subject.meshCytoplasm-
dc.subject.meshCytoskeleton-
dc.subject.meshEgtazic Acid-
dc.subject.meshNuclear Envelope-
dc.subject.meshWheat Germ Agglutinins-
dc.subject.meshXenopus-
dc.titleDimples, pores, star-rings, and thin rings on growing nuclear envelopes: evidence for structural intermediates in nuclear pore complex assembly.en
dc.typeArticleen
dc.contributor.departmentCRC Department of Structural Cell Biology, Paterson Institute for Cancer Research, Christie Hospital National Health Service Trust, Manchester, UK.en
dc.identifier.journalJournal of Cell Scienceen

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