scholarly journals A multiscale biophysical model for the recruitment of actin nucleating proteins at the membrane interface

Soft Matter ◽  
2020 ◽  
Vol 16 (21) ◽  
pp. 4941-4954 ◽  
Author(s):  
Ololade Fatunmbi ◽  
Ryan P. Bradley ◽  
Sreeja Kutti Kandy ◽  
Robert Bucki ◽  
Paul A. Janmey ◽  
...  
Keyword(s):  
Cell Division ◽  
Actin Cytoskeleton ◽  
Biophysical Model ◽  
Membrane Interface ◽  
Cellular Events ◽  
Cell Shaping

The dynamics and organization of the actin cytoskeleton are crucial to many cellular events such as motility, polarization, cell shaping, and cell division.

scholarly journals Regulation of the meiotic divisions of mammalian oocytes and eggs

2018 ◽  
Vol 46 (4) ◽  
pp. 797-806 ◽  
Author(s):  
Jessica R. Sanders ◽  
Keith T. Jones
Keyword(s):  
Cell Division ◽  
Luteinizing Hormone ◽  
Spindle Assembly Checkpoint ◽  
Asymmetric Cell Division ◽  
Homologous Chromosomes ◽  
Mammalian Oocyte ◽  
Cellular Events ◽  
The Hours ◽  
Meiosis I

Initiated by luteinizing hormone and finalized by the fertilizing sperm, the mammalian oocyte completes its two meiotic divisions. The first division occurs in the mature Graafian follicle during the hours preceding ovulation and culminates in an extreme asymmetric cell division and the segregation of the two pairs of homologous chromosomes. The newly created mature egg rearrests at metaphase of the second meiotic division prior to ovulation and only completes meiosis following a Ca2+ signal initiated by the sperm at gamete fusion. Here, we review the cellular events that govern the passage of the oocyte through meiosis I with a focus on the role of the spindle assembly checkpoint in regulating its timing. In meiosis II, we examine how the egg achieves its arrest and how the fertilization Ca2+ signal allows the initiation of embryo development.

WAVE signalling: from biochemistry to biology

2006 ◽  
Vol 34 (1) ◽  
pp. 73-76 ◽  
Author(s):  
S.H. Soderling ◽  
J.D. Scott
Keyword(s):  
Cell Division ◽  
Actin Cytoskeleton ◽  
Rho Gtpase ◽  
Current Knowledge ◽  
Biological Significance ◽  
Molecular Switches ◽  
Small Gtpases ◽  
Present Review ◽  
Cellular Targets ◽  
Syndrome Protein

The small GTPases Rho, Rac and Cdc42 (cell-division cycle 42) function as molecular switches to modulate the actin cytoskeleton. They achieve this by modulating the activity of downstream cellular targets. One group of Rho GTPase effectors, WAVE (Wiskott–Aldrich syndrome protein verprolin homologous)-1, WAVE-2 and WAVE-3, function as scaffolds for actin-based signalling complexes. The present review highlights current knowledge regarding the biochemistry of the WAVE signalling complexes and their biological significance.

scholarly journals Ubiquitin in regulation of spindle apparatus and its positioning: implications in development and disease

2015 ◽  
Vol 93 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Devika Srivastava ◽  
Oishee Chakrabarti
Keyword(s):  
Cell Division ◽  
Developmental Disorders ◽  
Ubiquitin Ligases ◽  
Pivotal Role ◽  
Direct Connection ◽  
Post Translational Modification ◽  
E3 Ligases ◽  
Cellular Events ◽  
Spindle Apparatus

Emerging data implicates ubiquitination, a post-translational modification, in regulating essential cellular events, one of them being mitosis. In this review we discuss how various E3 ligases modulate the cortical proteins such as dynein, LGN, NuMa, Gα, along with polymerization, stability, and integrity of spindles. These are responsible for regulating symmetric cell division. Some of the ubiquitin ligases regulating these proteins include PARK2, BRCA1/BARD1, MGRN1, SMURF2, and SIAH1; these play a pivotal role in the correct positioning of the spindle apparatus. A direct connection between developmental or various pathological disorders and the ubiquitination mediated cortical regulation is rather speculative, though deletions or mutations in them lead to developmental disorders and disease conditions.

Nuclear envelope proteins and their role in nuclear positioning and replication

2010 ◽  
Vol 38 (3) ◽  
pp. 741-746 ◽  
Author(s):  
Katja Graumann ◽  
John Runions ◽  
David E. Evans
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Root Hair ◽  
Nuclear Proteins ◽  
Present Review ◽  
Light Touch ◽  
Nuclear Positioning ◽  
Novel Proteins ◽  
Cellular Events ◽  
Chromosome Attachment

Controlled movement of the nucleus is important in a wide variety of plant cellular events. Positioning involving intact nuclei occurs in cell division, development, tip growing systems such as the root hair and in response to stimuli, including light, touch and infection. Positioning is also essential in the division and replication of nuclear components, ranging from chromosome attachment to the breakdown and reformation of the nuclear envelope. Although description and understanding of the processes involved have advanced rapidly in recent years, significant gaps remain in our knowledge, especially concerning nuclear proteins involved in anchoring and interacting with cytoskeletal and nucleoskeletal elements involved in movement. In the present review, processes involving the movement and positioning of nuclei and nuclear components are described together with novel proteins implicated in nucleoskeletal and cytoskeletal interactions.

scholarly journals Planar cell polarity signaling coordinates oriented cell division and cell rearrangement in clonally expanding growth plate cartilage

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Yuwei Li ◽  
Ang Li ◽  
Jason Junge ◽  
Marianne Bronner
Keyword(s):  
Cell Division ◽  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Cleavage Furrow ◽  
Tissue Architecture ◽  
Oriented Cell Division ◽  
Cellular Events ◽  
Column Formation ◽  
Single Column ◽  
Sister Cells

Both oriented cell divisions and cell rearrangements are critical for proper embryogenesis and organogenesis. However, little is known about how these two cellular events are integrated. Here we examine the linkage between these processes in chick limb cartilage. By combining retroviral-based multicolor clonal analysis with live imaging, the results show that single chondrocyte precursors can generate both single-column and multi-column clones through oriented division followed by cell rearrangements. Focusing on single column formation, we show that this stereotypical tissue architecture is established by a pivot-like process between sister cells. After mediolateral cell division, N-cadherin is enriched in the post-cleavage furrow; then one cell pivots around the other, resulting in stacking into a column. Perturbation analyses demonstrate that planar cell polarity signaling enables cells to pivot in the direction of limb elongation via this N-cadherin-mediated coupling. Our work provides new insights into the mechanisms generating appropriate tissue architecture of limb skeleton.

scholarly journals Apoptotic regulators promote cytokinetic midbody degradation in C. elegans

2012 ◽  
Vol 199 (7) ◽  
pp. 1047-1055 ◽  
Author(s):  
Yongping Chai ◽  
Dong Tian ◽  
Yihong Yang ◽  
Guoxin Feng ◽  
Ze Cheng ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Division ◽  
Daughter Cell ◽  
Apoptotic Cell ◽  
Imaging Analysis ◽  
C Elegans ◽  
Cellular Events ◽  
Cell Death Genes ◽  
Death Genes ◽  
Cell Engulfment

Cell death genes are essential for apoptosis and other cellular events, but their nonapoptotic functions are not well understood. The midbody is an important cytokinetic structure required for daughter cell abscission, but its fate after cell division remains elusive in metazoans. In this paper, we show through live-imaging analysis that midbodies generated by Q cell divisions in Caenorhabditis elegans were released to the extracellular space after abscission and subsequently internalized and degraded by the phagocyte that digests apoptotic Q cell corpses. We further show that midbody degradation is defective in apoptotic cell engulfment mutants. Externalized phosphatidylserine (PS), an engulfment signal for corpse phagocytosis, exists on the outer surface of the midbody, and inhibiting PS signaling delayed midbody clearance. Thus, our findings uncover a novel function of cell death genes in midbody internalization and degradation after cell division.

scholarly journals Inhibition of polar actin assembly by astral microtubules is required for cytokinesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anan Chen ◽  
Luisa Ulloa Severino ◽  
Thomas C. Panagiotou ◽  
Trevor F. Moraes ◽  
Darren A. Yuen ◽  
...  
Keyword(s):  
Cell Division ◽  
Actin Cytoskeleton ◽  
Actin Filament ◽  
Cell Cortex ◽  
Actin Assembly ◽  
Actin Network ◽  
Contractile Ring ◽  
Actin Networks ◽  
Membrane Blebbing ◽  
Actin Isoform

AbstractDuring cytokinesis, the actin cytoskeleton is partitioned into two spatially distinct actin isoform specific networks: a β-actin network that generates the equatorial contractile ring, and a γ-actin network that localizes to the cell cortex. Here we demonstrate that the opposing regulation of the β- and γ-actin networks is required for successful cytokinesis. While activation of the formin DIAPH3 at the cytokinetic furrow underlies β-actin filament production, we show that the γ-actin network is specifically depleted at the cell poles through the localized deactivation of the formin DIAPH1. During anaphase, CLIP170 is delivered by astral microtubules and displaces IQGAP1 from DIAPH1, leading to formin autoinhibition, a decrease in cortical stiffness and localized membrane blebbing. The contemporaneous production of a β-actin contractile ring at the cell equator and loss of γ-actin from the poles is required to generate a stable cytokinetic furrow and for the completion of cell division.

scholarly journals A molecular framework for control of oriented cell division in the Arabidopsis embryo

2021 ◽  
Author(s):  
Prasad Vaddepalli ◽  
Thijs de Zeeuw ◽  
Sören Strauss ◽  
Katharina Bürstenbinder ◽  
Che-Yang Liao ◽  
...  
Keyword(s):  
Cell Division ◽  
Actin Cytoskeleton ◽  
Plant Development ◽  
Transcriptome Profiling ◽  
Cell Geometry ◽  
Auxin Response ◽  
Division Plane ◽  
Asymmetric Divisions ◽  
Extensive Cell ◽  
Minimal Surface Area

SummaryPremitotic control of cell division orientation is critical for plant development, as cell walls prevent extensive cell remodelling or migration. Whilst many divisions are proliferative and add cells to existing tissues, some divisions are formative, and generate new tissue layers or growth axes. Such formative divisions are often asymmetric in nature, producing daughters with different fates. We have previously shown that in the Arabidopsis thaliana embryo, developmental asymmetry is correlated with geometric asymmetry, creating daughter cells of unequal volume. Such divisions are generated by division planes that deviate from a default “minimal surface area” rule. Inhibition of auxin response leads to reversal to this default, yet the mechanisms underlying division plane choice in the embryo have been unclear. Here we show that auxin-dependent division plane control involves alterations in cell geometry, but not in cell polarity or nuclear position. Through transcriptome profiling, we find that auxin regulates genes controlling cell wall and cytoskeleton properties. We confirm the involvement of microtubule (MT)-binding proteins in embryo division control. Topology of both MT and Actin cytoskeleton depend on auxin response, and genetically controlled MT or Actin depolymerization in embryos leads to disruption of asymmetric divisions, including reversion to the default. Our work shows how auxin-dependent control of MT- and Actin cytoskeleton properties interacts with cell geometry to generate asymmetric divisions during the earliest steps in plant development.

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