The structure and function of the nuclear lamins

1995 ◽  
Vol 53 ◽  
pp. 762-763
Author(s):  
R.D. Goldman ◽  
A. Goldman ◽  
S. Khuon ◽  
M. Montag-Lowy ◽  
R. Moir ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Lamina ◽  
Structure And Function ◽  
Supramolecular Organization ◽  
Intermediate Filament Proteins ◽  
Nuclear Envelope Breakdown ◽  
Nuclear Lamins ◽  
Interphase Cells ◽  
Type V ◽  
And Function

The nuclear lamins are the Type V intermediate filament proteins comprising the nuclear lamina. The lamina is located subjacent to the nucleoplasmic face of the nuclear envelope where it interfaces with chromatin. The lamins are major karyoskeletal proteins which are thought to play important roles in the formation and maintenance of nuclear shape and architecture, as well as in the supramolecular organization of chromatin. The lamins have long been thought to be stable polymeric constituents of the interphase nuclear matrix, due to their insolubility in solutions containing detergents and high salt concentrations. During mitosis, however, the nuclear lamins depolymerize during nuclear envelope breakdown. Subsequently, the lamins repolymerize around the decondensing chromosomes as the nuclear envelope reassembles at the end of mitosis. Although there is a significant amount known about the properties and potential functions of the lamins during mitosis, surprisingly little is known about their properties during interphase. In light of this, we have undertaken experiments which are aimed at determining the properties of the lamins in interphase cells.

scholarly journals Nuclear lamins and diabetes mellitus

STEMedicine ◽  
2020 ◽  
Vol 2 (5) ◽  
pp. e73
Author(s):  
Wei Xie ◽  
Brian Burke
Keyword(s):  
Diabetes Mellitus ◽  
Association Studies ◽  
Nuclear Lamina ◽  
Major Constituent ◽  
Genome Wide Association Studies ◽  
Intermediate Filament Proteins ◽  
Partial Lipodystrophy ◽  
Nuclear Lamins ◽  
Genes Encoding ◽  
Type V

In metazoans, a thin filamentous network referred to as the nuclear lamina plays an essential role in providing mechanical support to the nucleus. The major constituent of the nuclear lamina is type V intermediate filament proteins that are collectively referred to as lamins. A variety of diseases collectively termed laminopathies have been linked to mutations in genes encoding nuclear envelope proteins, in particular lamins, such as X-linked Emery Dreifus muscular dystrophy, dilated cardiomyopathy, Dunnigan type familial partial lipodystrophy and Hutchinson-Gilford progeria syndrome. Apart from laminopathies, genome-wide association studies have also been implicated nuclear lamins in the pathophysiology of type 2 diabetes mellitus, although little information in terms of the function of lamins in its pathogenesis. Our current review attempts to summarize risk factors of diabetes mellitus that could be attributable to lamin mutations and indirectly linked to lamin-associated factors identified in the last two decades.

Purification and immunological detection of pea nuclear intermediate filaments: evidence for plant nuclear lamins

1992 ◽  
Vol 103 (2) ◽  
pp. 407-414 ◽  
Author(s):  
A.K. McNulty ◽  
M.J. Saunders
Keyword(s):  
Nuclear Envelope ◽  
Intermediate Filaments ◽  
Plant Cells ◽  
Nuclear Lamina ◽  
Animal Cells ◽  
Nuclear Lamins ◽  
Antigenic Characterization ◽  
Major Structural Component ◽  
Nuclear Envelope Assembly ◽  
Type V

A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1–3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.

scholarly journals Structure-Function Relationships of Nuclear Lamins

2020 ◽  
Author(s):  
Shalaka Patil ◽  
Kundan Sengupta
Keyword(s):  
Protein Interactions ◽  
Genome Stability ◽  
Cell Function ◽  
Mechanical Stability ◽  
Nuclear Lamina ◽  
Protein Protein Interactions ◽  
Intermediate Filament Proteins ◽  
Nuclear Lamins ◽  
Type V ◽  
Nuclear Processes

Nuclear lamins are type V intermediate filament proteins that form a filamentous meshwork beneath the inner nuclear membrane. Additionally, a sub-population of A-type and B-type lamins is localized in the nuclear interior. The nuclear lamina protects the nucleus from mechanical stress and mediates nucleo-cytoskeletal coupling. Lamins form a scaffold that partially tethers chromatin at the nuclear envelope. The nuclear lamina also stabilizes protein-protein interactions involved in gene regulation and DNA repair. The lamin-based protein sub-complexes are implicated in both nuclear and cytoskeletal organization, the mechanical stability of the nucleus, genome organization, transcriptional regulation, genome stability, and cellular differentiation. Here we review recent research in the field of nuclear lamins and their role in modulating various nuclear processes and their impact on cell function.

scholarly journals Supramolecular Structures of the Dictyostelium Lamin NE81

Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 162
Author(s):  
Marianne Grafe ◽  
Petros Batsios ◽  
Irene Meyer ◽  
Daria Lisin ◽  
Otto Baumann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Model Organism ◽  
Super Resolution ◽  
Nuclear Lamina ◽  
Stimulated Emission ◽  
Structural Level ◽  
Animal Cells ◽  
Nuclear Lamins

Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells.

Review: The Dynamics of the Nuclear Lamins during the Cell Cycle— Relationship between Structure and Function

2000 ◽  
Vol 129 (2-3) ◽  
pp. 324-334 ◽  
Author(s):  
Robert D. Moir ◽  
Timothy P. Spann ◽  
Reynold I. Lopez-Soler ◽  
Miri Yoon ◽  
Anne E. Goldman ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Structure And Function ◽  
Nuclear Lamins ◽  
And Function

scholarly journals Nuclear Organization in Stress and Aging

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 664 ◽  
Author(s):  
Romero-Bueno ◽  
de la Cruz Ruiz ◽  
Artal-Sanz ◽  
Askjaer ◽  
Dobrzynska
Keyword(s):  
Gene Expression ◽  
Nuclear Envelope ◽  
Nuclear Organization ◽  
3 Dimensional ◽  
Cellular Processes ◽  
Nuclear Lamins ◽  
Nuclear Composition ◽  
Histone Modifiers ◽  
And Function ◽  
Gene Expression Alterations

The eukaryotic nucleus controls most cellular processes. It is isolated from the cytoplasm by the nuclear envelope, which plays a prominent role in the structural organization of the cell, including nucleocytoplasmic communication, chromatin positioning, and gene expression. Alterations in nuclear composition and function are eminently pronounced upon stress and during premature and physiological aging. These alterations are often accompanied by epigenetic changes in histone modifications. We review, here, the role of nuclear envelope proteins and histone modifiers in the 3-dimensional organization of the genome and the implications for gene expression. In particular, we focus on the nuclear lamins and the chromatin-associated protein BAF, which are linked to Hutchinson–Gilford and Nestor–Guillermo progeria syndromes, respectively. We also discuss alterations in nuclear organization and the epigenetic landscapes during normal aging and various stress conditions, ranging from yeast to humans.

Macromolecular constituents of basement membranes: a review of current knowledge on their structure and function

1983 ◽  
Vol 61 (8) ◽  
pp. 942-948 ◽  
Author(s):  
Paul G. Scott
Keyword(s):  
Type Iv Collagen ◽  
Current Knowledge ◽  
Heparan Sulphate ◽  
Structural Features ◽  
Structure And Function ◽  
Basement Membranes ◽  
Type Iv ◽  
Type V ◽  
And Function ◽  
Additional Form

Macromolecules which appear to be integral constituents of basement membranes include type IV collagen, the glycoprotein laminin, and heparan sulphate proteoglycan. Another glycoprotein, fibronectin, may occupy an intermediate position between some lining cells and their basement membranes but is not, however, restricted to this location. An additional form of collagen, genetic type V which differs significantly from type IV collagen in structure, appears to be associated with some basement membranes, possibly linking them to underlying connective tissue. The main structural features of each of these macromolecules, as presently understood, are reviewed here as a background to the experimental papers in this "mini-symposium."

scholarly journals Expression of an epidermal keratin protein in liver of transgenic mice causes structural and functional abnormalities.

1995 ◽  
Vol 128 (1) ◽  
pp. 157-169 ◽  
Author(s):  
K M Albers ◽  
F E Davis ◽  
T N Perrone ◽  
E Y Lee ◽  
Y Liu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cell Structure ◽  
Structure And Function ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Inflammatory Infiltration ◽  
Intermediate Filament Proteins ◽  
And Function

To examine the role of keratin intermediate filament proteins in cell structure and function, transgenic mice were isolated that express a modified form of the human K14 keratin protein in liver hepatocytes. A modified K14 cDNA (K14.P) sequence was linked downstream of the mouse transthyretin (TTR) gene promoter and enhancer elements to achieve targeted expression in hepatocytes. Hepatocytes expressing high levels of the transgene were found to have abnormal keratin filament networks as detected by indirect immunofluorescence using an antibody specific for the transgene product. Light and electron microscopic level histological analysis of isolated liver tissue showed in many cases degenerative changes that included inflammatory infiltration, ballooning degeneration, an increase in fat containing vacuoles, and glycogen accumulation. These changes were most evident in older mice over four months of age. No indication of typical Mallory body structures were identified at either the light or electron microscopic level. To evaluate secretory function in transgenic livers, bile acid secretion rates were measured in isolated perfused liver and found to be approximately twofold lower than aged-matched controls. These findings indicate that expression of an abnormal keratin in liver epithelial cells in the in vivo setting can alter the structure and function of a tissue and suggest a role of the keratin network in cellular secretion.

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