The position of the nucleus is regulated in different developmental stages and cellular events. During polarization, moves away from future leading edge this movement required for proper cell migration. Nuclear requires LINC complex components nesprin-2G SUN2, which form transmembrane actin-associated nuclear (TAN) lines at envelope. Here we show that envelope protein Samp1 (NET5) involved during fibroblast polarization Moreover, demonstrate a component TAN contain SUN2. Finally, associates...

During cytokinesis, a signal from the central spindle that forms between separating anaphase chromosomes promotes accumulation of contractile ring components at cell equator, while centrosomal microtubule asters inhibits poles. However, molecular identity inhibitory has remained unknown. To identify aster-based signal, we developed means to monitor removal proteins polar cortex after onset. Using this assay, show clearing is an active process requires activation Aurora A kinase by TPXL-1....

Cytokinesis in animal cells requires the assembly and constriction of a contractile actomyosin ring. Non-muscle myosin II is essential for cytokinesis, but role its motor activity remains unclear. Here, we examine cytokinesis C. elegans embryos expressing non-muscle mutants generated by genome editing. Two motor-dead myosins capable binding F-actin do not support one-cell embryo, two partially motor-impaired delay render rings more sensitive to reduced levels. Further analysis suggests that...

Cytokinesis, the process that partitions mother cell into two daughter cells, requires assembly and constriction of an equatorial actomyosin network. Different types non-motor F-actin crosslinkers localize to network, but their functional contribution remains poorly understood. Here, we describe a synergy between small rigid crosslinker plastin large flexible spectrin in C. elegans one-cell embryo. In contrast single inhibitions, co-inhibition βH-spectrin (SMA-1) results cytokinesis failure...

Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore biophysical properties constricting rings Caenorhabditis elegans embryos. Laser cutting causes snap open. However, instead disintegrating, ring topology recovers proceeds. In response severing, a finite gap forms is repaired by recruitment new material actin polymerization–dependent manner. An open able...

The establishment of separated pulmonary and systemic circulation in vertebrates, via cardiac outflow tract (OFT) septation, is a sensitive developmental process accounting for 10% all congenital anomalies. Neural Crest Cells (NCC) colonising the heart condensate along primitive endocardial tube force its scission into two tubes. Here, we show that NCC aggregation progressively decreases OFT distal-proximal axis following BMP signalling gradient. Dullard, nuclear phosphatase, tunes gradient...

The mechanism(s) through which mammalian kinase MELK promotes tumorigenesis is not understood. We find that the C. elegans orthologue of MELK, PIG-1, apoptosis by partitioning an anti-apoptotic factor. NSM neuroblast divides to produce a larger cell differentiates into neuron and smaller dies. in this context, PIG-1 required for CES-1 Snail, transcriptional repressor pro-apoptotic gene egl-1 BH3-only. pig-1 controlled both ces-1 Snail- par-4 LKB1-dependent pathway, may act phosphorylation...

Cytokinesis is the last step of cell division that physically partitions mother into two daughter cells and requires assembly constriction a contractile ring, circumferential array filamentous actin (F-actin), non-muscle myosin II motors (myosin), actin-binding proteins forms at equator. accompanied by long-range cortical flows from regions relaxation towards compression. In C. elegans one-cell embryo, it has been suggested anterior-directed are main driver ring assembly. Here, we use...

Cells actively position their nuclei within the cytoplasm for multiple cellular and physiological functions.1-3 Consequently, nuclear mispositioning is usually associated with cell dysfunction disease, from muscular disorders to cancer metastasis.4-7 Different types away leading edge during migration.8-11 In migrating fibroblasts, positioning driven by an actin retrograde flow originated at that drives dorsal cables edge. The connect envelope linker of nucleoskeleton cytoskeleton (LINC)...

Abstract Background Angiogenesis, the formation of new blood vessels, is a primordial process in development and its dysregulation has central role pathogenesis many diseases. Angiogenin (ANG), peculiar member RNase A superfamily, potent inducer angiogenesis involved different types cancer, amyotrophic lateral sclerosis also with possible innate immune defense. The evolutionary path this family been highly dynamic one, where positive selection played strong role. In work we used combined...

The nucleus is one of the hallmarks eukaryotic cells. history its discovery and characterisation intimately entangled with that cell biology as a discipline. Here, we provide broad historical perspective nucleus, from initial descriptions until present. We describe key events led to formulation chromosomal theory, nuclear pore complex, nucleo-cytoplasmic transport structure chromatin. also focus on rising importance periphery subject in research, multiple roles lamina proteins involved...

During cytokinesis, a contractile ring consisting of unbranched filamentous actin (F-actin) and myosin II constricts at the cell equator. Unbranched F-actin is generated by formin, without formin no cleavage furrow forms. In Caenorhabditis elegans, depletion septin restores ingression in mutants. How ingresses detectable unknown. We report that, this setting, anillin (ANI-1) forms meshwork circumferentially aligned linear structures decorated non-muscle (NMY-2). Analysis ANI-1 deletion...

Abstract Cytokinesis in animal cells requires the assembly of a contractile actomyosin ring, whose subsequent constriction physically separates two daughter cells. Non-muscle myosin II (myosin) is essential for cytokinesis, but role its motor activity remains poorly defined. Here, we examine cytokinesis C. elegans one-cell embryos expressing mutants generated by genome editing. Motor-dead myosin, which capable binding F-actin, does not support and co-expressing motor-dead wild-type are...

ABSTRACT During cytokinesis, a signal from the bundled microtubules that form between separating anaphase chromosomes promotes accumulation of contractile ring components at cell equator, while centrosomal microtubule asters inhibits poles. However, molecular identity inhibitory has remained unknown. To identify aster-based signal, we developed means to monitor removal proteins polar cortex after onset. Using this assay, show clearing is an active process requires activation Aurora A kinase...

Abstract Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore biophysical properties constricting rings C. elegans embryos. Laser cutting causes snap open, which is a sign tension release. However, instead disintegrating, ring topology recovers proceeds. In response severing, finite gap forms that proportional perimeters before cutting, demonstrating along...

Summary Establishment of separated pulmonary and systemic circulations in vertebrates relies on the key role neural crest cells (NCC) for septation embryonic cardiac outflow tract (OFT). Absence NCCs induces OFT defects, analogous to a loss Bone Morphogenetic Proteins (BMPs) activity, though it remains unclear how BMPs control NCC differentiation behaviour. To address this question, we monitored state upon gain BMP signaling, caused by deletion Dullard , using 3D-imaging single cell...

Summary Cells actively position their nuclei within the cytoplasm for multiple cellular and physiological functions. Different cell types away from leading edge to migrate properly. In migrating fibroblasts, nuclear positioning is driven by dorsal actin cables connected envelope LINC complex on Transmembrane Actin-associated Nuclear (TAN) lines. How are organized form TAN lines unknown. Here, we report a role Ctdnep1/Dullard, phosphatase, regulator Eps8L2, positioning. We demonstrate that...

Abstract The mechanism(s) through which mammalian kinase MELK promotes tumorigenesis is not understood. We find that the C. elegans orthologue of MELK, PIG-1, apoptosis by partitioning an anti-apoptotic factor. NSM neuroblast divides to produce a larger cell differentiates into neuron and smaller dies. in this context, PIG-1 required for CES-1 Snail, transcriptional repressor pro-apoptotic gene egl-1 BH3-only. pig-1 controlled both ces-1 Snail- par-4 LKB1-dependent pathway, may act...

Abstract Non-muscle myosin 2A (NM2A) is a key cytoskeletal enzyme that along with actin assembles into actomyosin filaments inside cells. NM2A fundamental in cellular processes requiring force generation such as cell adhesion, motility and division, plays important functions different stages of development during the progression viral bacterial infections. We previously identified novel tyrosine phosphorylation on residue 158 (pTyr ) motor domain NM2A. This dependent Src kinase promoted by...