scholarly journals Autoantibodies against constituents of nuclear pore complexes in patients with primary biliary cirrhosis and autoimmune hepatitis.

1995 ◽  
Vol 42 (2) ◽  
pp. 197-200 ◽  
Author(s):  
J Wesierska-Gadek ◽  
H Hohenauer ◽  
E Hitchman ◽  
E Penner
Keyword(s):  
Gel Electrophoresis ◽  
Nuclear Protein ◽  
Immunofluorescence Microscopy ◽  
Polyacrylamide Gel Electrophoresis ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Biliary Cirrhosis ◽  
Nuclear Pores ◽  
Indirect Immunofluorescence Microscopy ◽  
Pore Complexes

Sera obtained from patients with autoimmune liver disease were screened in indirect immunofluorescence microscopy for the presence of autoantibodies. Patients' sera, which strongly stained nuclei (ANA) with peripheral accentuation, were used for further experiments to define the corresponding antigen(s). Nuclei and nuclear subfractions were isolated from HeLaS3 cells and used as antigen source. Immunoblotting experiments were performed after separation of nuclear proteins by one- and two-dimensional polyacrylamide gel electrophoresis. Some ANA positive sera recognized the nuclear protein with molecular mass of approximately 200 kDa. Further analysis revealed that the patients' sera reacted with gp210, an integral protein of the nuclear pores. The incidence and clinical significance of these antibodies is discussed.

scholarly journals Saccharomyces cerevisiae Ndc1p Is a Shared Component of Nuclear Pore Complexes and Spindle Pole Bodies

1998 ◽  
Vol 143 (7) ◽  
pp. 1789-1800 ◽  
Author(s):  
Heidi J. Chial ◽  
Michael P. Rout ◽  
Thomas H. Giddings ◽  
Mark Winey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Immunofluorescence Microscopy ◽  
Spindle Pole ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Indirect Immunofluorescence Microscopy ◽  
Spindle Pole Bodies ◽  
Shared Component ◽  
Pore Complexes ◽  
Mutant Cells

We report a novel connection between nuclear pore complexes (NPCs) and spindle pole bodies (SPBs) revealed by our studies of the Saccharomyces cerevisiae NDC1 gene. Although both NPCs and SPBs are embedded in the nuclear envelope (NE) in yeast, their known functions are quite distinct. Previous work demonstrated that NDC1 function is required for proper SPB duplication (Winey, M., M.A. Hoyt, C. Chan, L. Goetsch, D. Botstein, and B. Byers. 1993. J. Cell Biol. 122:743–751). Here, we show that Ndc1p is a membrane protein of the NE that localizes to both NPCs and SPBs. Indirect immunofluorescence microscopy shows that Ndc1p displays punctate, nuclear peripheral localization that colocalizes with a known NPC component, Nup49p. Additionally, distinct spots of Ndc1p localization colocalize with a known SPB component, Spc42p. Immunoelectron microscopy shows that Ndc1p localizes to the regions of NPCs and SPBs that interact with the NE. The NPCs in ndc1-1 mutant cells appear to function normally at the nonpermissive temperature. Finally, we have found that a deletion of POM152, which encodes an abundant but nonessential nucleoporin, suppresses the SPB duplication defect associated with a mutation in the NDC1 gene. We show that Ndc1p is a shared component of NPCs and SPBs and propose a shared function in the assembly of these organelles into the NE.

Autoantibodies against nuclear pore complexes are associated with more active and severe liver disease in primary biliary cirrhosis

2001 ◽  
Vol 34 (3) ◽  
pp. 366-372 ◽  
Author(s):  
Pietro Invernizzi ◽  
Mauro Podda ◽  
Pier Maria Battezzati ◽  
Andrea Crosignani ◽  
Massimo Zuin ◽  
...  
Keyword(s):  
Liver Disease ◽  
Primary Biliary Cirrhosis ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Biliary Cirrhosis ◽  
Severe Liver ◽  
Severe Liver Disease ◽  
Pore Complexes

scholarly journals Motor-driven motility of fungal nuclear pores organizes chromosomes and fosters nucleocytoplasmic transport

2012 ◽  
Vol 198 (3) ◽  
pp. 343-355 ◽  
Author(s):  
Gero Steinberg ◽  
Martin Schuster ◽  
Ulrike Theisen ◽  
Sreedhar Kilaru ◽  
Andrew Forge ◽  
...  
Keyword(s):  
Nuclear Lamina ◽  
Ustilago Maydis ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Nuclear Pores ◽  
Gfp Reporter ◽  
Import And Export ◽  
Reporter Proteins ◽  
Pore Complexes

Exchange between the nucleus and the cytoplasm is controlled by nuclear pore complexes (NPCs). In animals, NPCs are anchored by the nuclear lamina, which ensures their even distribution and proper organization of chromosomes. Fungi do not possess a lamina and how they arrange their chromosomes and NPCs is unknown. Here, we show that motor-driven motility of NPCs organizes the fungal nucleus. In Ustilago maydis, Aspergillus nidulans, and Saccharomyces cerevisiae fluorescently labeled NPCs showed ATP-dependent movements at ∼1.0 µm/s. In S. cerevisiae and U. maydis, NPC motility prevented NPCs from clustering. In budding yeast, NPC motility required F-actin, whereas in U. maydis, microtubules, kinesin-1, and dynein drove pore movements. In the latter, pore clustering resulted in chromatin organization defects and led to a significant reduction in both import and export of GFP reporter proteins. This suggests that fungi constantly rearrange their NPCs and corresponding chromosomes to ensure efficient nuclear transport and thereby overcome the need for a structural lamina.

scholarly journals In vivo analysis of the stability and transport of nuclear poly(A)+ RNA.

1994 ◽  
Vol 126 (4) ◽  
pp. 877-899 ◽  
Author(s):  
S Huang ◽  
T J Deerinck ◽  
M H Ellisman ◽  
D L Spector
Keyword(s):  
Rna Polymerase Ii ◽  
Mammalian Cells ◽  
Stable Population ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Nuclear Pores ◽  
Electron Microscopic ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Pore Complexes

We have studied the distribution of poly(A)+ RNA in the mammalian cell nucleus and its transport through nuclear pores by fluorescence and electron microscopic in situ hybridization. Poly(A)+ RNA was detected in the nucleus as a speckled pattern which includes interchromatin granule clusters and perichromatin fibrils. When cells are fractionated by detergent and salt extraction as well as DNase I digestion, the majority of the nuclear poly(A)+ RNA was found to remain associated with the nonchromatin RNP-enriched fraction of the nucleus. After inhibition of RNA polymerase II transcription for 5-10 h, a stable population of poly(A)+ RNA remained in the nucleus and was reorganized into fewer and larger interchromatin granule clusters along with pre-mRNA splicing factors. This stable population of nuclear RNA may play an important role in nuclear function. Furthermore, we have observed that, in actively transcribing cells, the regions of poly(A)+ RNA which reached the nuclear pore complexes appeared as narrow concentrations of RNA suggesting a limited or directed pathway of movement. All of the observed nuclear pores contained poly(A)+ RNA staining suggesting that they are all capable of exporting RNA. In addition, we have directly visualized, for the first time in mammalian cells, the transport of poly(A)+ RNA through the nuclear pore complexes.

scholarly journals Piecing together nuclear pore complex assembly during interphase

2009 ◽  
Vol 185 (3) ◽  
pp. 377-379 ◽  
Author(s):  
Michael Rexach
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Supramolecular Structures ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Assembly Process ◽  
Nuclear Pores ◽  
Complex Assembly ◽  
Cell Biol ◽  
Pore Complexes

All nucleocytoplasmic traffic of macromolecules occurs through nuclear pore complexes (NPCs), which function as stents in the nuclear envelope to keep nuclear pores open but gated. Three studies in this issue (Flemming, D., P. Sarges, P. Stelter, A. Hellwig, B. Böttcher, and E. Hurt. 2009. J. Cell Biol. 185:387–395; Makio, T., L.H. Stanton, C.-C. Lin, D.S. Goldfarb, K. Weis, and R.W. Wozniak. 2009. J. Cell Biol. 185:459–491; Onishchenko, E., L.H. Stanton, A.S. Madrid, T. Kieselbach, and K. Weis. 2009. J. Cell Biol. 185:475–491) further our understanding of the NPC assembly process by reporting what happens when the supply lines of key proteins that provide a foundation for building these marvelous supramolecular structures are disrupted.

scholarly journals Dynamic Rearrangement of Nucleoporins during Fungal “Open” Mitosis

2008 ◽  
Vol 19 (3) ◽  
pp. 1230-1240 ◽  
Author(s):  
Ulrike Theisen ◽  
Anne Straube ◽  
Gero Steinberg
Keyword(s):  
Nuclear Envelope ◽  
Protein Import ◽  
Complex Dynamics ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Nuclear Pores ◽  
Basic Principles ◽  
Early Anaphase ◽  
Pore Complexes ◽  
Corn Smut

Mitosis in animals starts with the disassembly of the nuclear pore complexes and the breakdown of the nuclear envelope. In contrast to many fungi, the corn smut fungus Ustilago maydis also removes the nuclear envelope. Here, we report on the dynamic behavior of the nucleoporins Nup214, Pom152, Nup133, and Nup107 in this “open” fungal mitosis. In prophase, the nuclear pore complexes disassembled and Nup214 and Pom152 dispersed in the cytoplasm and in the endoplasmic reticulum, respectively. Nup107 and Nup133 initially spread throughout the cytoplasm, but in metaphase and early anaphase occurred on the chromosomes. In anaphase, the Nup107-subcomplex redistributed to the edge of the chromosome masses, where the new envelope was reconstituted. Subsequently, Nup214 and Pom152 are recruited to the nuclear pores and protein import starts. Recruitment of nucleoporins and protein import reached a steady state in G2 phase. Formation of the nuclear envelope and assembly of nuclear pores occurred in the absence of microtubules or F-actin, but not if both were disrupted. Thus, the basic principles of nuclear pore complex dynamics seem to be conserved in organisms displaying open mitosis.

Persistence of major nuclear envelope antigens in an envelope-like structure during mitosis in Drosophila melanogaster embryos

1989 ◽  
Vol 94 (3) ◽  
pp. 463-470 ◽  
Author(s):  
A. Harel ◽  
E. Zlotkin ◽  
S. Nainudel-Epszteyn ◽  
N. Feinstein ◽  
P.A. Fisher ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Early Embryo ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Interphase Nuclei ◽  
Mitotic Apparatus ◽  
Morphological Studies ◽  
Indirect Immunofluorescence Microscopy ◽  
Early Embryos ◽  
Pore Complexes

Using monoclonal antibodies, we followed the fate of three different nuclear envelope proteins during mitosis in Drosophila early embryos by indirect immunofluorescence microscopy. Two of these proteins, lamin and otefin, a newly characterized nuclear envelope polypeptide with an apparent Mr of 53,000, are apparently present in an envelope-like structure that is present throughout mitosis. Immunoelectron microscopy of interphase nuclei indicates that otefin, like lamin, is not a component of nuclear pore complexes. In contrast with lamin and otefin, gp188, a putative pore complex component, was completely redistributed through the surrounding cytoplasm during prophase in comparable early embryo specimens and was present in an envelope only in interphase. Together with previous morphological studies by other workers, these data suggest that the entire mitotic apparatus including condensed chromosomes and spindle is enclosed by an envelope throughout mitosis during early embryogenesis in Drosophila. This ‘spindle envelope’, as it has been named by others, contains both lamin and otefin but probably not pore complex proteins.

Assembly of nuclear pore complexes and annulate lamellae promotes normal pronuclear development in fertilized mammalian oocytes

1998 ◽  
Vol 111 (19) ◽  
pp. 2841-2854 ◽  
Author(s):  
P. Sutovsky ◽  
C. Simerly ◽  
L. Hewitson ◽  
G. Schatten
Keyword(s):  
Cell Types ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Annulate Lamellae ◽  
Oocyte Activation ◽  
Nuclear Pores ◽  
Microtubule Inhibitor ◽  
Cytoplasmic Transport ◽  
Oocyte Cytoplasm ◽  
Pore Complexes

In addition to functional nuclear pore complexes engaged in nucleo-cytoplasmic transport, the cytoplasmic stacks of pore complexes, called annulate lamellae, exist in numerous cell types. Although both annulate lamellae and nuclear pore complexes are present in fertilized mammalian oocytes, their relative roles in the process of fertilization and preimplantation development are not known. Using epifluorescence and electron microscopy, we explored their fate during bovine fertilization. The assembly of annulate lamellae in bovine oocytes was triggered by sperm-oocyte binding and continued concomitantly with the incorporation of the nuclear pores in the nuclear envelopes of the developing male and female pronuclei. This process was also induced by the parthenogenetic activation of metaphase-II-arrested oocytes. Depletion of Ca2+, previously implicated in oocyte activation and in the insertion of pore complexes into the nuclear envelope, prevented the formation of nuclear pore complexes, but not the assembly of annulate lamellae in oocyte cytoplasm. Injection of the nuclear pore antagonist, wheat germ agglutinin, into the cytoplasm of mature oocytes that were subsequently fertilized caused the arrest of pronuclear development, indicating the requirement of nuclear pore complexes for normal pronuclear development. Treatment of the fertilized oocytes with the microtubule inhibitor, nocodazole, prevented gathering of annulate lamellae around the developing pronuclei, insertion of nuclear pores into their nuclear envelopes, and further pronuclear development. The formation of the male pronuclei was reconstituted in Xenopus egg extracts and reflected the behavior of nuclear pores during natural fertilization. These data suggest that nuclear pore complexes are required for normal pronuclear development from its beginning up until pronuclear apposition. Annulate lamellae may be involved in the turnover of nuclear pore complexes during fertilization, which is in turn facilitated by the reorganization of oocyte microtubules and influx of Ca2+ into oocyte cytoplasm.

scholarly journals Nup214 Is Required for CRM1-Dependent Nuclear Protein Export In Vivo

2006 ◽  
Vol 26 (18) ◽  
pp. 6772-6785 ◽  
Author(s):  
Saskia Hutten ◽  
Ralph H. Kehlenbach
Keyword(s):  
Protein Import ◽  
Nuclear Protein ◽  
Biochemical Properties ◽  
Protein Export ◽  
Nuclear Pore ◽  
Minor Effect ◽  
Nuclear Pore Complexes ◽  
High Affinity ◽  
Pore Complexes

ABSTRACT Nucleoporins mediate transport of macromolecules across the nuclear pore complex, yet the function of many individual nucleoporins is largely unresolved. To address this question, we depleted cells of the cytoplasmic nucleoporins Nup214/CAN and Nup358/RanBP2 by RNA interference. Depletion of Nup214 resulted in codepletion of its binding partner, Nup88. Nuclear pore complexes assembled in the absence of Nup214/Nup88 or Nup358 were fully functional in nuclear protein import, whereas nuclear mRNA export was slightly impaired. Depletion of Nup358 had only a minor effect on nuclear protein export. In contrast, depletion of Nup214/Nup88 led to strongly reduced CRM1-mediated export of the shuttling transcription factor NFAT as well as a human immunodeficiency virus-Rev derivative. A specific role of Nup214 in protein export is furthered by the biochemical properties of a high-affinity complex containing Nup214, CRM1, RanGTP, and an export cargo. Our results show that the Nup214/Nup88 complex is required for efficient CRM1-mediated transport, supporting a model involving a high-affinity binding site for CRM1 at Nup214 in the terminal steps of export.

544 Prognostic value of autoantibodies against proteins of nuclear pore complexes (anti-NPCS) in early primary biliary cirrhosis (PBC)

2004 ◽  
Vol 40 ◽  
pp. 159-160 ◽  
Author(s):  
P. Invernizzi ◽  
J. Wesierska-Gadek ◽  
P.M. Battezzati ◽  
S. Oertelt ◽  
P.L. Busatto ◽  
...  
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Prognostic Value ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Biliary Cirrhosis ◽  
Early Primary ◽  
Pore Complexes
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