Spatial distribution of lamin A and B1 in the K562 cell nuclear matrix stabilized with metal ions

Spatial distribution of heavy metal ions (HMI) in inorganic glass forming melts was studied by measuring HMI distribution coefficient between two unmixable melts: sodium-borate glass forming melt and non-glass forming molten sodium sulfate. Combining the data on glass host composition dependence of HMI distribution coefficient with the data of Rayleigh and Mandel’shtam-Brillouin scattering (RMBS) spectroscopy of glasses doped with HMI and undoped ones made it possible to evidence the segregation of HMI into alkali-enriched inhomogeneities of glass hosts and offer the approach to choosing compositions of glass host in which HMI segregation will be minimized.

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Chromatin condensation during apoptosis is accompanied by degradation of lamin A+B, without enhanced activation of cdc2 kinase.

The Journal of Cell Biology ◽

10.1083/jcb.126.4.827 ◽

1994 ◽

Vol 126 (4) ◽

pp. 827-837 ◽

Cited By ~ 234

Author(s):

F A Oberhammer ◽

K Hochegger ◽

G Fröschl ◽

R Tiefenbacher ◽

M Pavelka

Keyword(s):

Nuclear Matrix ◽

Chromatin Condensation ◽

Fibroblast Cell ◽

Kinase Assay ◽

Similar Process ◽

Lamin A ◽

Apoptotic Cells ◽

Cell Extracts ◽

Dna Strand ◽

Mitotic Cells

Chromatin condensation paralleled by DNA fragmentation is one of the most important criteria which are used to identify apoptotic cells. However, comparable changes are also observed in interphase nuclei which have been treated with cell extracts from mitotic cells. In this respect it is known that in mitosis, the lamina structure is broken down as a result of lamin solubilization and it is possible that a similar process is happening in apoptotic cells. The experiments described in this study have used confluent cultures of an embryonic fibroblast cell line which can be induced to undergo either apoptosis at low serum conditions or mitosis. Solubilization of lamin A+B was analyzed by immunoblotting and indirect immunofluorescence. These studies showed that in mitotic cells lamina breakdown is accompanied by lamin solubilization. In apoptotic cells, a small amount of lamin is solubilized before the onset of apoptosis, thereafter, chromatin condensation is accompanied by degradation of lamin A+B to a 46-kD fragment. Analysis of cellular lysates by probing blots with anti-PSTAIR followed by anti-phosphotyrosine showed that in contrast to mitosis, dephosphorylation on tyrosine residues did not occur in apoptotic cells. At all timepoints after the onset of apoptosis there was no significant increase in the activation of p34cdc2 as determined in the histone H1 kinase assay. Coinduction of apoptosis and mitosis after release of cells from aphidicolin block showed that apoptosis could be induced in parallel with S-phase. The sudden breakdown of chromatin structure may be the result of detachment of the chromatin loops from their anchorage at the nuclear matrix, as bands of 50 kbp and corresponding multimers were detectable by field inversion gel electrophoresis (FIGE). In apoptotic cells all of the DNA was fragmented, but only 14% of the DNA was smaller than 50 kbp. DNA strand breaks were detected at the periphery of the condensed chromatin by in situ tailing (ISTAIL). Chromatin condensation during apoptosis appears to be due to a rapid proteolysis of nuclear matrix proteins which does not involve the p34cdc2 kinase.

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First person – Luv Kishore Srivastava

Journal of Cell Science ◽

10.1242/jcs.258880 ◽

2021 ◽

Vol 134 (10) ◽

Keyword(s):

Spatial Distribution ◽

Early Career ◽

Lamin A ◽

First Person ◽

Nuclear Deformation ◽

Early Career Researchers ◽

Mcgill University ◽

Global And Local ◽

Selection Of

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Luv Kishore Srivastava is first author on ‘Spatial distribution of lamin A/C determines nuclear stiffness and stress-mediated deformation’, published in JCS. Luv Kishore is a PhD student in the lab of Allen Ehrlicher at McGill University, Montreal, Canada, investigating the role of lamin A/C in global and local nuclear deformation.

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Spatial distribution of lamin A determines nuclear stiffness and stress-mediated deformation

10.1101/765263 ◽

2019 ◽

Author(s):

Luv Kishore Srivastava ◽

Zhaoping Ju ◽

Ajinkya Ghagre ◽

Allen J. Ehrlicher

Keyword(s):

Spatial Distribution ◽

Nuclear Envelope ◽

Bulk Modulus ◽

Quantitative Relationship ◽

Major Axis ◽

Vertical Axis ◽

Lamin A ◽

Expression Levels ◽

Nuclear Mechanics ◽

Dominant Component

AbstractThe nucleus is the largest organelle and information center of the cell; while diverse cellular components have been identified as mechanotransduction elements, the deformation of the nucleus itself is emerging as a critical mechanosensory mechanism, suggesting that the nuclear stiffness is essential in determining responses to intracellular and extracellular stresses. The nuclear membrane protein, lamin A, is known to be a dominant component in nuclear stiffening; however, the quantitative relationship between lamin A expression and nuclear deformation is still unclear. Here we measure the nuclear moduli as a function of lamin A expression and applied stress, revealing a linear dependence of bulk modulus on lamin A expression. We also find that the bulk modulus is anisotropic, with the vertical axis of the nucleus being more compliant than the minor and major axis. To examine how lamin A influences nuclear mechanics at the sub-micron scale we correlated the spatial distribution of lamin A with 3D nuclear envelope deformation, revealing that local areas of the nuclear envelope with higher expression levels of lamin A have correspondingly lower local deformations, and that increased lamin A expression levels result in a narrower distribution of smaller deformations. These findings describe the complex dispersion of nuclear deformations as a function of lamin A expression and distribution and implicate a role in mechanotransduction.

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Spatial Distribution of Actin and Tubulin in Human Sperm Nuclear Matrix-intermediate Filament Whole Mounts—A New Paradigm

Microscopy Research and Technique ◽

10.1002/jemt.20438 ◽

2007 ◽

Vol 70 (7) ◽

pp. 589-598 ◽

Cited By ~ 8

Author(s):

Kaushiki Kadam ◽

Serena D'souza ◽

Usha Natraj

Keyword(s):

Spatial Distribution ◽

Nuclear Matrix ◽

Intermediate Filament ◽

Human Sperm ◽

New Paradigm ◽

Whole Mounts

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Identification of distinct messenger RNAs for nuclear lamin C and a putative precursor of nuclear lamin A.

The Journal of Cell Biology ◽

10.1083/jcb.98.3.980 ◽

1984 ◽

Vol 98 (3) ◽

pp. 980-985 ◽

Cited By ~ 32

Author(s):

J F Laliberté ◽

A Dagenais ◽

M Filion ◽

V Bibor-Hardy ◽

R Simard ◽

...

Keyword(s):

Nuclear Matrix ◽

Gel Electrophoresis ◽

Lamin A ◽

Messenger Rnas ◽

Two Dimensional Gel Electrophoresis ◽

Nuclear Matrix Proteins ◽

Nuclear Lamin ◽

Sds Page ◽

Putative Precursor

The lamins are the major components of the nuclear matrix and are known as lamins A, B, and C with Mr 72,000, 68,000, and 62,000 when analysed by SDS PAGE. These three polypeptides are very similar, as determined by polypeptide mapping and immunological reactivity. Lamins A and C are so homologous that a precursor-product relationship has been proposed. Using an antiserum against nuclear matrix proteins that specifically immunoprecipitates the three lamins, we examined their synthesis in the rabbit reticulocytes lysate. Four bands of Mr 62,000, 68,000, 70,000, and 74,000 were specifically immunoprecipitated when polysomes or polyadenylated RNA were translated in vitro. By two-dimensional gel electrophoresis, the 68,000- and the 62,000-mol-wt proteins were identified as lamins B and C, respectively, and the 74,000-mol-wt polypeptide had properties of a precursor of lamin A. The mRNAs of lamin C and of the putative precursor of lamin A were completely separated by gel electrophoresis under denaturing conditions, and their respective sizes were determined. These results suggest that lamin A is not a precursor of lamin C.

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Lamin A/C controls nuclear matrin-3 levels and localization, but not alternative splicing of cassette exons

10.1101/378240 ◽

2018 ◽

Author(s):

Dipen Rajgor ◽

Clare Gooding ◽

Robert Hayward ◽

Miguel B Coelho ◽

Christopher WJ Smith ◽

...

Keyword(s):

Alternative Splicing ◽

Nuclear Matrix ◽

Matrix Protein ◽

Structural Integrity ◽

Biological Significance ◽

Nuclear Lamina ◽

Lamin A ◽

Nuclear Matrix Protein ◽

Matrin 3 ◽

Small Nuclear Ribonucleoproteins

AbstractDisruptions in connections between the nuclear lamina and nuclear matrix occur in myopathic disorders. However, the biological significance of nuclear lamina - nuclear matrix coupling still remains largely undetermined. Previously it has been demonstrated that the nuclear matrix protein, matrin-3, binds to lamin A/C and this interaction is disrupted in laminopathies resulting in enhanced separation between the lamina and matrix. Matrin-3 has recently been identified as a core regulator of alternative splicing, whereas the involvement of lamin A/C in splicing still remains controversial. In this study, we demonstrate that lamin A/C is not only required for maintaining the nuclear organization of matrin-3, but also of other splicing activators and small nuclear ribonucleoproteins (snRNP) components. Interestingly, mis-localization of these splicing components did not appear to significantly disrupt alternative splicing events of cassette exons regulated by matrin-3. Thus, the lamin A/C-matrin3 interaction is unlikely to be involved in controlling alternative splicing but could be important in coordinating other nuclear activities. Interestingly, matrin-3 knock-down results in misshapen nuclei suggesting its interaction with lamin A/C maybe important in maintaining nuclear structural integrity.

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