Fig.1. Cell cycle showing the formation of the actomyosin ring during telophase or early cytokinesis stage.
In molecular biology, an actomyosin ring or contractile ring, is a prominent structure during cytokinesis.[1] It forms perpendicular to the axis of the spindle apparatus[2] towards the end of telophase, in which sister chromatids are identically separated at the opposite sides of the spindle forming nuclei (Figure 1). The actomyosin ring follows an orderly sequence of events: identification of the active division site, formation of the ring, constriction of the ring, and disassembly of the ring.[1] It is composed of actin and myosin II bundles, thus the term actomyosin. The actomyosin ring operates in contractile motion,[3] although the mechanism on how or what triggers the constriction is still an evolving topic.[4] Other cytoskeletal proteins are also involved in maintaining the stability of the ring[5] and driving its constriction.[6] Apart from cytokinesis, in which the ring constricts as the cells divide (Figure 2), actomyosin ring constriction has also been found to activate during wound closure.[7] During this process, actin filaments are degraded, preserving the thickness of the ring. After cytokinesis is complete, one of the two daughter cells inherits a remnant known as the midbody ring.[8]
Activation of the cell-cycle kinase (e.g. Rho-kinases) during telophase initiates constriction of the actomyosin ring by creating a groove that migrates in an inward motion. Rho-kinases such as ROCK1 has been found to regulate actomyosin contraction through phosphorylation of the myosin light chain (MLC).[9] This mechanism promotes cell-cell contacts and integrity leading to adhesion formation.
^ abCheffings, T. H.; Burroughs, N. J.; Balasubramanian, M. K. (2016). "Actomyosin Ring Formation and Tension Generation in Eukaryotic Cytokinesis". Current Biology. 26 (15): R719–R737. doi:10.1016/j.cub.2016.06.071. PMID 27505246. S2CID 3908927.
^Mana-Capelli, Sebastian; McCollum, Dannel (2013). "Actomyosin Ring". Encyclopedia of Systems Biology. p. 8. doi:10.1007/978-1-4419-9863-7_779. ISBN 978-1-4419-9862-0.
^Munjal, A.; Lecuit, T. (2014). "Actomyosin networks and tissue morphogenesis". Development. 141 (9): 1789–1793. doi:10.1242/dev.091645. PMID 24757001. S2CID 5257808.
^Mendes Pinto, I.; Rubinstein, B.; Li, R. (2013). "Force to divide: Structural and mechanical requirements for actomyosin ring contraction". Biophysical Journal. 105 (3): 547–554. doi:10.1016/j.bpj.2013.06.033. PMC 3736747. PMID 23931302.
^Martin, A. C. (2016). "Embryonic ring closure: Actomyosin rings do the two-step". The Journal of Cell Biology. 215 (3): 301–303. doi:10.1083/jcb.201610061. PMC 5100299. PMID 27799371.
^Schwayer, C.; Sikora, M.; Slováková, J.; Kardos, R.; Heisenberg, C. P. (2016). "Actin Rings of Power". Developmental Cell. 37 (6): 493–506. doi:10.1016/j.devcel.2016.05.024. PMID 27326928.
^Pelletier, L.; Yamashita, Y. M. (2012). "Centrosome asymmetry and inheritance during animal development". Current Opinion in Cell Biology. 24 (4): 541–546. doi:10.1016/j.ceb.2012.05.005. PMC 3425708. PMID 22683192.
^Shi, J.; Surma, M.; Zhang, L.; Wei, L. (2013). "Dissecting the roles of ROCK isoforms in stress-induced cell detachment". Cell Cycle. 12 (10): 1492–1900. doi:10.4161/cc.24699. PMC 3680529. PMID 23598717.
In molecular biology, an actomyosinring or contractile ring, is a prominent structure during cytokinesis. It forms perpendicular to the axis of the spindle...
anaphase the actomyosinring and septum continues to develop in budding yeast, in fission yeast during metaphase-anaphase the actomyosinring begins to develop...
myosin, begin the process of forming the cleavage furrow, creating an actomyosinring. Other cytoskeletal proteins and actin binding proteins are involved...
enrichment of anillins at the contractile ring during cytokinesis. Anillins are also enriched at other actomyosinrings, most significantly, those at the leading...
dependent, redundant processes: recruitment and contraction of the actomyosinring and formation of the septum by vesicle fusion with the plasma membrane...
cell cortex, also known as the actin cortex, cortical cytoskeleton or actomyosin cortex, is a specialized layer of cytoplasmic proteins on the inner face...
Rong (1 May 2005). "Cell Cycle-regulated Trafficking of Chs2 Controls ActomyosinRing Stability during Cytokinesis". Molecular Biology of the Cell. 16 (5):...
It also inhibits skeletal muscle actomyosin MgATPase activity and calcium activated force generation by actomyosin in the intact skeletal muscle contractile...
PMC 2291169. PMID 7790358. Mulvihill DP, Hyams JS (2002). "Cytokinetic actomyosinring formation and septation in fission yeast are dependent on the full...
contraction of actomyosin filaments that often form a contractile ring. The contractile ring is a very dynamic structure in which actomyosin filaments are...
by myosin II molecular motors. Additionally, they function as part of actomyosin-driven contractile molecular motors, wherein the thin filaments serve...
Rounding forces are driven by reorganization of F-actin and myosin (actomyosin) into a contractile homogeneous cell cortex that 1) rigidifies the cell...
are proportional to the length of the stereocilia. Intrinsic chirality. Actomyosin networks have been implicated in generating an intrinsic chirality in...
division viral budding via host ESCRT complex viral process actomyosin contractile ring assembly maintenance of epithelial cell apical/basal polarity...
"protrusion formation along intracellular borders caused by the reduction in actomyosin contractility of the CECs." However, these morphological changes to the...
The presence of chromosomes induces the formation of an actomyosin cortical cap, a myosin II ring structure and a set of spindle fibers, the rotation of...
involution of the blastopore. In these cells, apical constriction occurs when actomyosin contractility folds the cell membrane to reduce the apical surface area...
cytokinesis actomyosin contractile ring assembly cortical cytoskeleton organization septin ring organization protein localization to mitotic actomyosin contractile...
as the morula. Compaction results from increased contractility of the actomyosin cortex, which pull cells together into a tighter configuration. Increased...
zingibain's rapid proteolysis of major muscle proteins within meat, especially actomyosin and Type I collagen, which is found in muscle joints. While other papain...
Developing Interstitial Branches. Waterman-Storer, C. & Salmon, E. (1997). Actomyosin-based retrograde flow of microtubules in the lamella of migrating epithelial...
motoring along F-actin filaments generates contractile forces in so-called actomyosin fibers, both in muscle as well as most non-muscle cell types. Actin structures...
causes toxic effects. As latrunculin inhibits actin polymerization and actomyosin contractile ability, exposure to latrunculin may result in cellular relaxation...
multicellular organism development microtubule-based movement actomyosin contractile ring assembly spermatogenesis neuroblast proliferation cell cycle...
with cytoskeleton regulation, mostly actin stress fibers formation and actomyosin contractility. It acts upon several effectors. Among them, ROCK1 (Rho-associated...
positive regulation of viral budding via host ESCRT complex actomyosin contractile ring contraction protein targeting to lysosome nuclear envelope organization...
ions will flow into the cell and that will then cause the contraction of actomyosin filaments which are responsible for the exocytosis of insulin. Finally...
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