Regulation of nuclear envelope precursor functions during cell division

1992 ◽  
Vol 102 (2) ◽  
pp. 273-284 ◽  
Author(s):  
G.P. Vigers ◽  
M.J. Lohka
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Xenopus Oocyte ◽  
Cyclin B ◽  
Nuclear Pore ◽  
S6 Kinase ◽  
Similar Treatment ◽  
Nuclear Envelope Assembly ◽  
Liver Nuclei ◽  
Xenopus Egg

Previously, we have shown that nuclear envelope assembly in cell-free extracts of Xenopus eggs requires two distinct vesicle-containing fractions, called Nuclear Envelope Precursor Fractions A and B (NEP-A and NEP-B). These fractions are characterized further in this paper and the manner in which they are regulated during metaphase is examined. Antisera against the NEP-B fraction recognized several proteins common to NEP-B and Xenopus oocyte or liver nuclei, but not to NEP-A or cytosol. A known glycoprotein component of the nuclear pore complex, p62, also co-fractionated with NEP-B, whereas the Xenopus egg lamin LIII did not. Together, these results provide further evidence that the NEP-B fraction contains precursors of the nuclear envelope. The regulation of NEP-A and -B function during metaphase, when the nuclear envelope is disassembled, was examined by treating each fraction with metaphase cytosol or purified protein kinase preparations isolated from metaphase-arrested eggs. Treatment of NEP-B with metaphase cytosol, under conditions where proteins are irreversibly phosphorylated, inhibited the subsequent assembly of the nuclear envelope by preventing the binding of NEP-B to chromatin. In contrast, similar treatment of NEP-A did not affect its ability to form nuclear envelopes. The changes in NEP-B during metaphase did not appear to be regulated directly by either p34cdc2/cyclin B, S6 kinase II or MAP kinase.

scholarly journals A modified procedure for the isolation of a pore complex-lamina fraction from rat liver nuclei.

1976 ◽  
Vol 70 (3) ◽  
pp. 581-591 ◽  
Author(s):  
N Dwyer ◽  
G Blobel
Keyword(s):  
Nuclear Envelope ◽  
Rat Liver ◽  
Nuclear Pore Complex ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Envelope Membrane ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Pore Complexes

A modified procedure for the isolation of a nuclear pore complex-lamina fraction from rat liver nuclei is described. Evidence is provided that the isolated lamina, a 150-A thick, proteinaceous structure, apposes the inner nuclear envelope membrane, connecting nuclear pore complexes and surrounding the entire nucleus.

scholarly journals Regulation and coordination of nuclear envelope and nuclear pore complex assembly

Nucleus ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Michaela Clever ◽  
Yasuhiro Mimura ◽  
Tomoko Funakoshi ◽  
Naoko Imamoto
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Nuclear Pore ◽  
Complex Assembly

scholarly journals The Three Fungal Transmembrane Nuclear Pore Complex Proteins of Aspergillus nidulans Are Dispensable in the Presence of an Intact An-Nup84-120 Complex

2009 ◽  
Vol 20 (2) ◽  
pp. 616-630 ◽  
Author(s):  
Hui-Lin Liu ◽  
Colin P.C. De Souza ◽  
Aysha H. Osmani ◽  
Stephen A. Osmani
Keyword(s):  
High Temperature ◽  
Nuclear Envelope ◽  
Aspergillus Nidulans ◽  
Nuclear Pore Complex ◽  
Mitotic Spindle ◽  
Spindle Pole ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Spindle Pole Bodies ◽  
Pore Complexes

In Aspergillus nidulans nuclear pore complexes (NPCs) undergo partial mitotic disassembly such that 12 NPC proteins (Nups) form a core structure anchored across the nuclear envelope (NE). To investigate how the NPC core is maintained, we affinity purified the major core An-Nup84-120 complex and identified two new fungal Nups, An-Nup37 and An-ELYS, previously thought to be vertebrate specific. During mitosis the An-Nup84-120 complex locates to the NE and spindle pole bodies but, unlike vertebrate cells, does not concentrate at kinetochores. We find that mutants lacking individual An-Nup84-120 components are sensitive to the membrane destabilizer benzyl alcohol (BA) and high temperature. Although such mutants display no defects in mitotic spindle formation, they undergo mitotic specific disassembly of the NPC core and transient aggregation of the mitotic NE, suggesting the An-Nup84-120 complex might function with membrane. Supporting this, we show cells devoid of all known fungal transmembrane Nups (An-Ndc1, An-Pom152, and An-Pom34) are viable but that An-ndc1 deletion combined with deletion of individual An-Nup84-120 components is either lethal or causes sensitivity to treatments expected to destabilize membrane. Therefore, the An-Nup84-120 complex performs roles, perhaps at the NPC membrane as proposed previously, that become essential without the An-Ndc1 transmembrane Nup.

scholarly journals Cytochemical studies on the relation of nucleoside triphosphatase activity to ribonucleoproteins in isolated rat liver nuclei.

1980 ◽  
Vol 28 (1) ◽  
pp. 27-35 ◽  
Author(s):  
A Vorbrodt ◽  
G G Maul
Keyword(s):  
Nuclear Envelope ◽  
Rat Liver ◽  
Enzyme Reaction ◽  
Point Of View ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat

Cytochemical tests for nucleosidetriphosphatase (NTPase) and Bernhard's preferential staining for ribonucleoproteins (RNP) were applied to isolated rat liver nuclei. The strongest and most easily reproducible positive reaction for NTPase was detected at pH 7.7 with ATP and GTP. This reaction was activated by Mg2+ and Ca2+ and inhibited by Be2+, Zn2+, quercetin, and ribonuclease. The major sites of enzyme reaction were intranuclear RNA-containing structures. Incubation of nuclei in ATP-stimulated RNA-release medium eliminated a considerable part of the material showing both NTPase reaction and staining for RNP; the perichromatin granules disappeared, while interchromatin granules remained. NTPase activity in the nuclear envelope seems to be associated with the annular part of nuclear pore complexes (permanent component) and with RNP particles translocated through nuclear pores or attached to the surface of nuclei (transitional component). From a morphological point of view, these observations support previous biochemical data suggesting the existence of a connection between NTPase activity and the translocation of RNP particles through the nuclear envelope.

scholarly journals The single transmembrane segment of gp210 is sufficient for sorting to the pore membrane domain of the nuclear envelope.

1992 ◽  
Vol 119 (6) ◽  
pp. 1441-1449 ◽  
Author(s):  
R W Wozniak ◽  
G Blobel
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Immunofluorescence Microscopy ◽  
Nuclear Pore ◽  
Transmembrane Helices ◽  
Wild Type ◽  
Transmembrane Segment ◽  
Membrane Domain ◽  
3T3 Cells ◽  
Type Mutant

The glycoprotein gp210 is located in the "pore membrane," a specialized domain of the nuclear envelope to which the nuclear pore complex (NPC) is anchored. gp210 contains a large cisternal domain, a single transmembrane segment (TM), and a COOH-terminal, 58-amino acid residue cytoplasmic tail (CT) (Wozniak, R. W., E. Bartnik, and G. Blobel. 1989. J. Cell Biol. 108:2083-2092; Greber, U. F., A. Senior, and L. Gerace. 1990. EMBO (Eur. Mol. Biol. Organ.) J. 9:1495-1502). To locate determinants for sorting of gp210 to the pore membrane, we constructed various cDNAs coding for wild-type, mutant, and chimeric gp210, and monitored localization of the expressed protein in 3T3 cells by immunofluorescence microscopy using appropriate antibodies. The large cisternal domain of gp210 (95% of its mass) did not reveal any sorting determinants. Surprisingly, the TM of gp210 is sufficient for sorting to the pore membrane. The CT also contains a sorting determinant, but it is weaker than that of the TM. We propose specific lateral association of the transmembrane helices of two proteins to yield either a gp210 homodimer or a heterodimer of gp210 and another protein. The cytoplasmically oriented tails of these dimers may bind cooperatively to the adjacent NPCs. In addition, we demonstrate that gp210 co-localizes with cytoplasmically dispersed nucleoporins, suggesting a cytoplasmic association of these components.

scholarly journals The Torsin/ NEP1R1-CTDNEP1/ Lipin axis regulates nuclear envelope lipid metabolism for nuclear pore complex insertion

2020 ◽  
Author(s):  
Julie Jacquemyn ◽  
Joyce Foroozandeh ◽  
Katlijn Vints ◽  
Jef Swerts ◽  
Patrik Verstreken ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Lipid Droplets ◽  
Nuclear Pore ◽  
List Type ◽  
Unknown Mechanism ◽  
Structure Lipid ◽  
Cellular Events ◽  
Upstream Regulator

AbstractTorsin ATPases of the endoplasmic reticulum (ER) and nuclear envelope (NE) lumen inhibit Lipin-mediated phosphatidate (PA) to diacylglycerol (DAG) conversion by an unknown mechanism. This excess PA metabolism is implicated in TOR1A/TorsinA diseases, but it is unclear whether it explains why Torsin concomitantly affects nuclear structure, lipid droplets (LD), organelle and cell growth. Here a fly miniscreen identified that Torsins affect these events via the NEP1R1-CTDNEP1 phosphatase complex. Further, Torsin homo-oligomerization rather than ATPase activity was key to function. NEP1R1-CTDNEP1 activates Lipin by dephosphorylation. We show that Torsin prevents CTDNEP1 from accumulating in the NE and excludes Lipin from the nucleus. Moreover, this repression of nuclear PA metabolism is required for interphase nuclear pore biogenesis. We conclude that Torsin is an upstream regulator of the NEP1R1-CTDNEP1/ Lipin pathway. This connects the ER/NE lumen with PA metabolism, and affects numerous cellular events including it has a previously unrecognized role in nuclear pore biogenesis.HighlightsNuclear envelope PA-DAG-TAG synthesis is independently regulated by Torsin and Torip/LAP1Torsin removes CTDNEP1 from the nuclear envelope and excludes Lipin from the nucleusExcess nuclear envelope NEP1R1-CTDNEP1/ Lipin activity impairs multiple aspects of NPC biogenesisNEP1R1-CTDNEP1/ Lipin inhibition prevents cellular defects associated with TOR1A and TOR1AIP1 / LAP1 disease

scholarly journals Monoclonal antibodies identify a group of nuclear pore complex glycoproteins.

1987 ◽  
Vol 104 (5) ◽  
pp. 1143-1156 ◽  
Author(s):  
C M Snow ◽  
A Senior ◽  
L Gerace
Keyword(s):  
Monoclonal Antibodies ◽  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Peptide Mapping ◽  
Polyclonal Antibodies ◽  
Integral Membrane Protein ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Nuclear Surface ◽  
Punctate Pattern

Using monoclonal antibodies we identified a group of eight polypeptides of rat liver nuclear envelopes that have common epitopes. Most or all of these proteins are structurally distinct, as shown by tryptic peptide mapping and analysis with polyclonal antibodies. While these polypeptides are relatively tightly bound to nuclear membranes, only one is an integral membrane protein. The eight antigens cofractionate with the nuclear pore complex under various conditions of ionic strength and detergent. It can be seen by immunofluorescence microscopy that the monoclonal antibodies reacting with these antigens stain the nuclear surface of interphase cells in a finely punctate pattern. When the nuclear envelope is disassembled and subsequently reformed during mitosis, the proteins are reversibly dispersed throughout the cytoplasm in the form of minute foci. By EM immunogold localization on isolated nuclear envelopes, the monoclonal antibodies label exclusively the nuclear pore complex, at both its nucleoplasmic and cytoplasmic margins. Considered together, our biochemical and localization data indicate that the eight nuclear envelope polypeptides are pore complex components. As shown in the accompanying paper (Holt, G. D., C. M. Snow, A. Senior, R. S. Haltiwanger, L. Gerace, and G. W. Hart, J. Cell Biol., 104:1157-1164) these eight polypeptides contain a novel form of glycosylation, O-linked N-acetylglucosamine. The relative abundance and disposition of these O-linked glycoproteins in the pore complex are consistent with their having a role in nucleocytoplasmic transport.

Evidence that vault ribonucleoprotein particles localize to the nuclear pore complex

1993 ◽  
Vol 106 (1) ◽  
pp. 23-29 ◽  
Author(s):  
D.C. Chugani ◽  
L.H. Rome ◽  
N.L. Kedersha
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Radial Symmetry ◽  
Nuclear Pore ◽  
Isolated Nuclei ◽  
Tissue Sections ◽  
Ribonucleoprotein Particles ◽  
Eukaryotic Species ◽  
Central Plug

Vaults are cytoplasmic ribonucleoprotein organelles that are highly conserved among diverse eukaryotic species. Their mass (12.9 MDa), diameter (26-35 nm) and shape (two halves, each with eightfold radial symmetry) have recently been determined and are similar to those ascribed to the central plug (or transporter) of the nuclear pore complex (NPC). The size and eightfold symmetry of the vault particle make it conducive to interacting physically in a complementary manner with NPCs. The present study demonstrates that vaults specifically associate with nuclei by both immunoblotting and immunofluorescence. Immunogold EM confirmed that vaults associate with the nuclear envelope in tissue sections and with NPCs of isolated nuclei.

Aphidicolin-Sensitive DNA Polymerase Is Incorporated into the Chromatin during Nuclear Envelope Assembly in Xenopus Egg Extract

1995 ◽  
Vol 219 (1) ◽  
pp. 283-291
Author(s):  
Yoshihiro Takasuga ◽  
Machiko Murata ◽  
Jinpei Yamashita ◽  
Toshiow Andoh ◽  
Tatsuo Yagura
Keyword(s):  
Nuclear Envelope ◽  
Dna Polymerase ◽  
Xenopus Egg Extract ◽  
Egg Extract ◽  
Nuclear Envelope Assembly ◽  
Xenopus Egg
Sign in / Sign up

Export Citation Format

Share Document