scholarly journals Recruitment of BAF to the nuclear envelope couples the LINC complex to endoreplication

Development ◽  
2020 ◽  
Vol 147 (23) ◽  
pp. dev191304
Author(s):  
C. P. Unnikannan ◽  
Adriana Reuveny ◽  
Dvorah Grunberg ◽  
Talila Volk
Keyword(s):  
Cell Growth ◽  
Nuclear Envelope ◽  
Dna Content ◽  
Tissue Injury ◽  
Linc Complex ◽  
A Cell ◽  
Domain Protein ◽  
Dna Endoreplication

ABSTRACTDNA endoreplication has been implicated as a cell strategy for cell growth and in tissue injury. Here, we demonstrate that barrier-to-autointegration factor (BAF) represses endoreplication in Drosophila myofibers. We show that BAF localization at the nuclear envelope is eliminated in flies with mutations of the linker of nucleoskeleton and cytoskeleton (LINC) complex in which the LEM-domain protein Otefin is excluded, or after disruption of the nucleus-sarcomere connections. Furthermore, BAF localization at the nuclear envelope requires the activity of the BAF kinase VRK1/Ball, and, consistently, non-phosphorylatable BAF-GFP is excluded from the nuclear envelope. Importantly, removal of BAF from the nuclear envelope correlates with increased DNA content in the myonuclei. E2F1, a key regulator of endoreplication, overlaps BAF localization at the myonuclear envelope, and BAF removal from the nuclear envelope results in increased E2F1 levels in the nucleoplasm and subsequent elevated DNA content. We suggest that LINC-dependent and phosphosensitive attachment of BAF to the nuclear envelope, through its binding to Otefin, tethers E2F1 to the nuclear envelope thus inhibiting its accumulation in the nucleoplasm.

scholarly journals Mechanotransduction via the LINC complex regulates DNA replication in myonuclei

2018 ◽  
Vol 217 (6) ◽  
pp. 2005-2018 ◽  
Author(s):  
Shuoshuo Wang ◽  
Elizabeth Stoops ◽  
Unnikannan CP ◽  
Barak Markus ◽  
Adriana Reuveny ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Dna Content ◽  
Cell Cycle Progression ◽  
Mechanical Stimuli ◽  
Linc Complex ◽  
Cycle Progression ◽  
Binding Profile ◽  
Genome Wide ◽  
Chromatin Regulator ◽  
Dna Endoreplication

Nuclear mechanotransduction has been implicated in the control of chromatin organization; however, its impact on functional contractile myofibers is unclear. We found that deleting components of the linker of nucleoskeleton and cytoskeleton (LINC) complex in Drosophila melanogaster larval muscles abolishes the controlled and synchronized DNA endoreplication, typical of nuclei across myofibers, resulting in increased and variable DNA content in myonuclei of individual myofibers. Moreover, perturbation of LINC-independent mechanical input after knockdown of β-Integrin in larval muscles similarly led to increased DNA content in myonuclei. Genome-wide RNA-polymerase II occupancy analysis in myofibers of the LINC mutant klar indicated an altered binding profile, including a significant decrease in the chromatin regulator barrier-to-autointegration factor (BAF) and the contractile regulator Troponin C. Importantly, muscle-specific knockdown of BAF led to increased DNA content in myonuclei, phenocopying the LINC mutant phenotype. We propose that mechanical stimuli transmitted via the LINC complex act via BAF to regulate synchronized cell-cycle progression of myonuclei across single myofibers.

scholarly journals Phosphorylation of luminal region of the SUN-domain protein Mps3 promotes nuclear envelope localization during meiosis

2020 ◽  
Author(s):  
H. B. D. Prasada Rao ◽  
Takeshi Sato ◽  
Kiran Challa ◽  
Miki Shinohara ◽  
Akira Shinohara
Keyword(s):  
Protein Kinase ◽  
Nuclear Envelope ◽  
Control Force ◽  
Linc Complex ◽  
Specific Localization ◽  
Domain Protein ◽  
Protein Ensembles ◽  
And Function ◽  
Sun Domain ◽  
Luminal Region

SummaryDuring meiosis, protein ensembles in the nuclear envelope (NE) containing SUN- and KASH-domain proteins, called linker nucleocytoskeleton and cytoskeleton (LINC) complex, promote chromosome motion. How LINC complexes acquire the meiotic property is largely unknown. Here we showed that cyclin-dependent protein kinase (CDK) and Dbf4-dependent Cdc7 protein kinase (DDK) promote proper meiosis-specific localization of yeast SUN-domain protein Mps3 on NE and control force-dependent movement of chromosomes during meiosis. We also found a NE luminal region of Mps3 juxtaposed to inner nuclear membrane (INM) is required for meiosis-specific localization of Mps3 on NE. Negative charges introduced by meiosis-specific non-canonical phosphorylation of the luminal region of Mps3 changes its interaction with INM, which may induce NE localization by promoting the formation of a canonical LINC complex with Mps3. Our study reveals unique phosphorylation-dependent regulation on the localization and function of Mps3 protein in meiotic NE remodeling.

scholarly journals Phosphorylation of luminal region of the SUN-domain protein Mps3 promotes nuclear envelope localization during meiosis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Hanumanthu BD Prasada Rao ◽  
Takeshi Sato ◽  
Kiran Challa ◽  
Yurika Fujita ◽  
Miki Shinohara ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nuclear Envelope ◽  
Meiotic Chromosome ◽  
Linc Complex ◽  
Dependent Protein ◽  
Domain Protein ◽  
Protein Ensembles ◽  
Chromosome Motion ◽  
Sun Domain ◽  
Luminal Region

During meiosis, protein ensembles in the nuclear envelope (NE) containing SUN- and KASH-domain proteins, called linker nucleocytoskeleton and cytoskeleton (LINC) complex, promote the chromosome motion. Yeast SUN-domain protein, Mps3, forms multiple meiosis-specific ensembles on NE, which show dynamic localisation for chromosome motion; however, the mechanism by which these Mps3 ensembles are formed during meiosis remains largely unknown. Here, we showed that the cyclin-dependent protein kinase (CDK) and Dbf4-dependent Cdc7 protein kinase (DDK) regulate meiosis-specific dynamics of Mps3 on NE, particularly by mediating the resolution of Mps3 clusters and telomere clustering. We also found that the luminal region of Mps3 juxtaposed to the inner nuclear membrane is required for meiosis-specific localisation of Mps3 on NE. Negative charges introduced by meiosis-specific phosphorylation in the luminal region of Mps3 alter its interaction with negatively charged lipids by electric repulsion in reconstituted liposomes. Phospho-mimetic substitution in the luminal region suppresses the localisation of Mps3 via the inactivation of CDK or DDK. Our study revealed multi-layered phosphorylation-dependent regulation of the localisation of Mps3 on NE for meiotic chromosome motion and NE remodelling.

The steady-states of a multi-compartment, age–size distribution model of cell-growth

2008 ◽  
Vol 19 (4) ◽  
pp. 435-458 ◽  
Author(s):  
R. E. BEGG ◽  
D. J. N. WALL ◽  
G. C. WAKE
Keyword(s):  
Cell Growth ◽  
Size Distribution ◽  
Dna Content ◽  
Distribution Model ◽  
Current Phase ◽  
Size Distributions ◽  
A Cell ◽  
The Stability ◽  
Speculative Discussion ◽  
Specific Phase

A model of cell-growth, describing the evolution of the age–size distribution of cells in different phases of cell-growth, is studied. The model is based on that used in several papers by Basse et al. and is composed of a system of partial differential equations, each describing the changes in the age–size distribution of cells in a specific phase of cell-growth. Here, the ‘age’ of a cell is considered to be the time spent in its current phase of cell-growth, while ‘size’ is considered to be the DNA content of the cell. The existence of steady age–size distributions (SASDs), where the age–size distributions retain the same shape but are scaled up or down as time increases, is investigated and it is shown that SASDs exist. A speculative discussion of the stability of these SASDs is also included, but their stability is not conclusively proved.

Head Size and DNA Content in Bacteriophage T4

1972 ◽  
Vol 30 ◽  
pp. 200-201
Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner
Keyword(s):  
Electron Microscopy ◽  
Dna Content ◽  
Bacteriophage T4 ◽  
Head Size ◽  
Virus Particles ◽  
Altered Protein ◽  
A Cell ◽  
Bacterial Viruses ◽  
A Site ◽  
Protein Shell

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).

scholarly journals Putrescine, a Cell Growth Factor

Nature ◽  
1972 ◽  
Vol 235 (5338) ◽  
pp. 366-366
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
A Cell

scholarly journals LINCking the Nuclear Envelope to Sperm Architecture

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 658
Author(s):  
Francesco Manfrevola ◽  
Florian Guillou ◽  
Silvia Fasano ◽  
Riccardo Pierantoni ◽  
Rosanna Chianese
Keyword(s):  
Nuclear Envelope ◽  
Male Fertility ◽  
Nuclear Architecture ◽  
Sperm Cells ◽  
Bridge Structure ◽  
Linc Complex ◽  
Head Formation ◽  
Morphological Maturation ◽  
Integral Proteins ◽  
Sun Domain

Nuclear architecture undergoes an extensive remodeling during spermatogenesis, especially at levels of spermatocytes (SPC) and spermatids (SPT). Interestingly, typical events of spermiogenesis, such as nuclear elongation, acrosome biogenesis, and flagellum formation, need a functional cooperation between proteins of the nuclear envelope and acroplaxome/manchette structures. In addition, nuclear envelope plays a key role in chromosome distribution. In this scenario, special attention has been focused on the LINC (linker of nucleoskeleton and cytoskeleton) complex, a nuclear envelope-bridge structure involved in the connection of the nucleoskeleton to the cytoskeleton, governing mechanotransduction. It includes two integral proteins: KASH- and SUN-domain proteins, on the outer (ONM) and inner (INM) nuclear membrane, respectively. The LINC complex is involved in several functions fundamental to the correct development of sperm cells such as head formation and head to tail connection, and, therefore, it seems to be important in determining male fertility. This review provides a global overview of the main LINC complex components, with a special attention to their subcellular localization in sperm cells, their roles in the regulation of sperm morphological maturation, and, lastly, LINC complex alterations associated to male infertility.

scholarly journals Annexin A2 in Fibrinolysis, Inflammation and Fibrosis

2021 ◽  
Vol 22 (13) ◽  
pp. 6836
Author(s):  
Hana I. Lim ◽  
Katherine A. Hajjar
Keyword(s):  
Cell Surface ◽  
Tissue Injury ◽  
Critical Role ◽  
Annexin A2 ◽  
Hemorrhagic Disease ◽  
Membrane Repair ◽  
Endothelial Cell Surface ◽  
Human Disorders ◽  
A Cell ◽  
Organ Fibrosis

As a cell surface tissue plasminogen activator (tPA)-plasminogen receptor, the annexin A2 (A2) complex facilitates plasmin generation on the endothelial cell surface, and is an established regulator of hemostasis. Whereas A2 is overexpressed in hemorrhagic disease such as acute promyelocytic leukemia, its underexpression or impairment may result in thrombosis, as in antiphospholipid syndrome, venous thromboembolism, or atherosclerosis. Within immune response cells, A2 orchestrates membrane repair, vesicle fusion, and cytoskeletal organization, thus playing a critical role in inflammatory response and tissue injury. Dysregulation of A2 is evident in multiple human disorders, and may contribute to the pathogenesis of various inflammatory disorders. The fibrinolytic system, moreover, is central to wound healing through its ability to remodel the provisional matrix and promote angiogenesis. A2 dysfunction may also promote tissue fibrogenesis and end-organ fibrosis.

Are phytoplankton population density maxima predictable through analysis of host and viral genomic DNA content?

2006 ◽  
Vol 86 (3) ◽  
pp. 491-498 ◽  
Author(s):  
Chris M. Brown ◽  
Janice E. Lawrence ◽  
Douglas A. Campbell
Keyword(s):  
Population Density ◽  
Dna Content ◽  
Viral Genome ◽  
Particle Assembly ◽  
Phytoplankton Population ◽  
Strong Linear Correlation ◽  
Viral Progeny ◽  
A Cell ◽  
Viral Proliferation ◽  
Viral Particle Assembly

Phytoplankton:virus interactions are important factors in aquatic nutrient cycling and community succession. The number of viral progeny resulting from an infection of a cell critically influences the propagation of infection and concomitantly the dynamics of phytoplankton populations. Host nucleotide content may be the resource limiting viral particle assembly. We present evidence for a strong linear correlation between measured viral burst sizes and viral burst sizes predicted from the host DNA content divided by the viral genome size, across a diversity of phytoplankton:viral pairs. An analysis of genome sizes therefore supports predictions of taxon-specific phytoplankton population density thresholds beyond which viral proliferation can trim populations or terminate phytoplankton blooms. We present corollaries showing that host:virus interactions may place evolutionary pressure towards genome reduction of both phytoplankton hosts and their viruses.

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