Relationship of Nuclear Invaginations to Perinuclear Rings Composed of Intermediate Filaments in MIA PaCa-2 and Some Other Cells.

Kamei, Hiroya

doi:10.1247/csf.19.123

Cited by 24 publications

(21 citation statements)

References 39 publications

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“…Consistent with literature reports (20,47), actin stress fiber disassembly but no microtubule depolymerization was detected in ACR-treated cells (data not shown). As the emergence of nuclear folds has been described to occur in some vimentin null cells, in cells expressing vimentin mutants or containing thick IF bundles, and in ACRtreated neurons (33,43,76,78), we used the percentage of cells with nuclear invaginations as an estimate of the extent of IF disruption. As expected, an exposure time-dependent increase in percentage values was observed, from 1.5% Ϯ 1% after 2 h to 32% Ϯ 7% after 8 h of continual treatment (Fig.…”

Section: Viral Entry Does Not Alter Vimentin If Structurementioning

confidence: 99%

Onset of Human Cytomegalovirus Replication in Fibroblasts Requires the Presence of an Intact Vimentin Cytoskeleton

Miller

Hertel

2009

J Virol

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Like all viruses, herpesviruses extensively interact with the host cytoskeleton during entry. While microtubules and microfilaments appear to facilitate viral capsid transport toward the nucleus, evidence for a role of intermediate filaments in herpesvirus entry is lacking. Here, we examined the function of vimentin intermediate filaments in fibroblasts during the initial phase of infection of two genotypically distinct strains of human cytomegalovirus (CMV), one with narrow (AD169) and one with broad (TB40/E) cell tropism. Chemical disruption of the vimentin network with acrylamide, intermediate filament bundling in cells from a patient with giant axonal neuropathy, and absence of vimentin in fibroblasts from vimentin ؊/؊ mice severely reduced entry of either strain. In vimentin null cells, viral particles remained in the cytoplasm longer than in vimentin ؉/؉ cells. TB40/E infection was consistently slower than that of AD169 and was more negatively affected by the disruption or absence of vimentin. These findings demonstrate that an intact vimentin network is required for CMV infection onset, that intermediate filaments may function during viral entry to facilitate capsid trafficking and/or docking to the nuclear envelope, and that maintenance of a broader cell tropism is associated with a higher degree of dependence on the vimentin cytoskeleton. viduals (8, 58). Virtually all cell types, with the exception of lymphocytes and polymorphonuclear leukocytes, can support CMV replication in vivo (80), and this remarkably broad tropism is at the basis of the numerous clinical manifestations of CMV infection (8, 58). The range of permissive cells in vitro is more limited, with human fibroblasts (HF) and endothelial cells being the most widely used for propagation of clinical isolates. Two extensively studied strains, AD169 and Towne, were generated by serial passage of tissue isolates in HF for the purpose of vaccine development (22,68). During this process, both strains accumulated numerous genomic changes (11) and lost the ability to grow in cell types other than HF. By contrast, propagation in endothelial cells produced strains with more intact genomes and tropism, such as TB40/E, VR1814, TR, and PH (59, 80). Human cytomegalovirus (CMV) is a ubiquitous herpesvirus that can cause serious disease in immunocompromised indiThe viral determinants of endothelial and epithelial cell tropism have recently been mapped to the UL128-UL131A (UL128-131A) genomic locus (32,92,93). Each of the products of the UL128, UL130, and UL131A genes is independently required for tropism and participates in the formation of a complex at the surface of the virion with the viral glycoproteins gH and gL (74, 93), which can also independently associate with gO (45). The gH/gL/UL128-131A complex appears to be required for entry into endothelial cells by endocytosis, followed by low-pH-dependent fusion of the virus envelope with endosomal membranes (73, 74) although some virus strains expressing the UL128-UL131A genes do not require endosome acid...

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Section: Viral Entry Does Not Alter Vimentin If Structurementioning

confidence: 99%

Onset of Human Cytomegalovirus Replication in Fibroblasts Requires the Presence of an Intact Vimentin Cytoskeleton

Miller

Hertel

2009

J Virol

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“…Prominent bundles of intermediate filaments have been described in the nuclear folds in an adenocarcinoma cell line. 49 The nature of NE receptors for cytoskeletal connections is unknown, but nuclear pores would be the best candidates since no outer NE-specific proteins are known. It should be straightforward to test the relative contributions of the actin, tubulin, and intermediate filament classes of cytoskeletal elements to the dynamic development of nuclear irregularity during interphase, and the ability to induce NE dynamics could facilitate discovery of potential cytoskeletal binding sites on the NE.…”

Section: Potential Cytoplasmic-based Forces Acting On the Nementioning

confidence: 99%

Nuclear Envelope Irregularity Is Induced by RET/PTC During Interphase

Fischer

Taysavang

Jhiang

2003

The American Journal of Pathology

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Nuclear envelope (NE) irregularity is an important diagnostic feature of cancer, and its molecular basis is not understood. One possible cause is abnormal postmitotic NE re-assembly, such that a rounded contour is never achieved before the next mitosis. Alternatively, dynamic forces could deform the NE during interphase following an otherwise normal postmitotic NE re-assembly. To distinguish these possibilities, normal human thyroid epithelial cells were microinjected with the papillary thyroid carcinoma oncogene (RET/PTC1 short isoform, known to induce NE irregularity), an attenuated version of RET/PTC1 lacking the leucine zipper dimerization domain (RET/PTC1 ⌬zip), H (V-12) RAS, and labeled dextran. Cells were fixed at 6 or 18 to 24 hours, stained for lamins and the products of microinjected plasmids, and scored blindly using previously defined criteria for NE irregularity. 6.5% of non-injected thyrocytes showed NE irregularity. Neither dextran nor RAS microinjections increased NE irregularity. In contrast, RET/PTC1 microinjection induced NE irregularity in 27% of cells at 6 hours and 37% of cells at 18 to 24 hours. RET/PTC1 ⌬zip induced significantly less irregularity. Since irregularity develops quickly, and since no mitoses and only rare possible postmitotic cells were scored, postmitotic NE re-assembly does not appear necessary for RET/PTC signaling to induce an irregular NE contour. An irregularity in nuclear shape is a common diagnostic abnormality in cancer cells, yet surprisingly little is known about the structural basis of this change or its functional significance. The large-scale organization of the nuclear envelope (NE) defines nuclear shape. The NE consists of two lipid bilayers, nuclear pores, and the nuclear lamina (reviewed in 1-4 ). One lipid bilayer is the outer nuclear membrane, which is continuous with the endoplasmic reticulum. To date, no biochemical difference is known to distinguish the outer nuclear membrane or its membraneassociated proteins from the endoplasmic reticulum. In contrast, the inner nuclear membrane facing chromatin contains a number of membrane-associated proteins that are specific to this lipid bilayer. In turn, the membraneassociated proteins of the inner nuclear membrane are tightly associated with the intermediate filament proteins, called lamins, to form the chromatin-associated nuclear lamina. 2,5,6 The inner nuclear lipid bilayer is continuous with the outer nuclear membrane at nuclear pores. Nuclear pores regulate vectorial import and export between the nucleus and cytoplasm. 7 Irregularity of NE shape, from any cause, could theoretically affect a number of cell physiologies. Nuclear lamina proteins are involved in determining replication competence 8 -14 and organizing transcription by binding to and segregating heterochromatin 15 (reviewed in 16 ). Consistent with a role in organizing transcription, large-scale localization of genes near the NE is associated with transcriptional silencing. 17 Theoretically the function of nuclear pores could be altered within...

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“…Although many mammalian cells are known to contain deep tubular invaginations of the nuclear envelope (Fricker et al, 1997), some of which are associated with perinuclear rings of IFs (Kamei, 1994), and nuclei of the cell line SW 13 are generally irregular in shape (Sarria et al, 1994), the invaginations described in this article in HSF and SW 13 T3 M [vimentin ϩ ] cells correlate with treatment with the HIV-1 PR. Given the propensity for HIV-1 PR to cleave IF proteins (Shoeman et al, 1990a), we had originally thought that the nuclear matrix core filaments, which are morphologically indistinguishable from the cytoplasmic IFs (Jackson and Cook, 1988;He et al, 1990;Wang and Traub, 1991;Padros et al, 1997), or other compo- Figure 4.…”

Section: Discussionmentioning

confidence: 87%

Amino-terminal Polypeptides of Vimentin Are Responsible for the Changes in Nuclear Architecture Associated with Human Immunodeficiency Virus Type 1 Protease Activity in Tissue Culture Cells

Shoeman

Hüttermann

Hartig

et al. 2001

MBoC

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Electron microscopy of human skin fibroblasts syringe-loaded with human immunodeficiency virus type 1 protease (HIV-1 PR) revealed several effects on nuclear architecture. The most dramatic is a change from a spherical nuclear morphology to one with multiple lobes or deep invaginations. The nuclear matrix collapses or remains only as a peripheral rudiment, with individual elements thicker than in control cells. Chromatin organization and distribution is also perturbed. Attempts to identify a major nuclear protein whose cleavage by the protease might be responsible for these alterations were unsuccessful. Similar changes were observed in SW 13 T3 M INTRODUCTIONFibroblasts microinjected with human immunodeficiency virus type 1 protease (HIV-1 PR) examined at the light microscopic level were found to exhibit rapid changes in nuclear morphology and chromatin organization, followed by disruption of actin-containing stress fibers and an eventual collapse of cytoplasmic vimentin intermediate filaments (IFs) . Although the effects on the cytoplasmic cytoskeletal structures are readily explained by the cleavage of their integral or associated proteins (Shoeman et al., 1990a(Shoeman et al., , 1993, the events giving rise to the nuclear alterations have remained an enigma. These nuclear changes occur most rapidly at the lowest concentrations of HIV-1 PR tested and closely resemble those described for a variety of tissues examined in HIV-1-infected individuals (Shoeman et al., 1992, for discussion and references).Because several IF subunit proteins are excellent substrates for HIV-1 PR (Shoeman et al., 1990a) and because the nuclear matrix core filaments are morphologically indistinguishable from the cytoplasmic IFs (Jackson and Cook, 1988;He et al., 1990;Wang and Traub, 1991;Padros et al., 1997), it seemed likely that one or more components of the nuclear matrix might be cleaved by HIV-1 PR and be responsible for the alterations in nuclear structure. Although it was possible to visualize alterations in residual cellular and nuclear structures in HIV-1 PR-treated cells, it was not possible to correlate the cleavage of a nuclear protein (e.g., NuMA; the nuclear mitotic apparatus protein) with the changes in nuclear architecture. Instead, we were able to show, by a com- MATERIALS AND METHODS Proteins and PeptidesVimentin was purified from mouse Ehrlich ascites tumor cells (Nelson et al., 1982). Mouse vimentin has 97% sequence identity to human vimentin and yields products similar to those obtained from human vimentin when cleaved by HIV-1 PR (Shoeman et al., 1990a). T-vimentin, which lacks the first 70 amino acid residues of vimentin, was prepared as described (Traub et al., 1992a). The amino-terminal vimentin peptide NT1, containing residues 1-96, was prepared from mouse vimentin as previously described (Traub et al., 1992b). Peptide R23R, whose sequence is identical to that of mouse vimentin (vim) residues 22 to 44 (i.e., vim ), peptide R25R (vim 44 -68 ), peptide P410 (vim [3][4][5][6][7][8][9][10][11][12][13][14][15]...

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Relationship of Nuclear Invaginations to Perinuclear Rings Composed of Intermediate Filaments in MIA PaCa-2 and Some Other Cells.

Abstract: ABSTRACT. There have been few investigations of the cause of nuclear invagination and lobule formation.

Cited by 24 publications

References 39 publications

Onset of Human Cytomegalovirus Replication in Fibroblasts Requires the Presence of an Intact Vimentin Cytoskeleton

Onset of Human Cytomegalovirus Replication in Fibroblasts Requires the Presence of an Intact Vimentin Cytoskeleton

Nuclear Envelope Irregularity Is Induced by RET/PTC During Interphase

Amino-terminal Polypeptides of Vimentin Are Responsible for the Changes in Nuclear Architecture Associated with Human Immunodeficiency Virus Type 1 Protease Activity in Tissue Culture Cells

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