scholarly journals Dispersion relations of cytoskeleton dynamics

2016 ◽  
pp. 1
Author(s):  
Gabriel Popescu ◽  
Ru Wang ◽  
Lei Lei ◽  
Shamira Sridharan ◽  
Yingxiao Wang ◽  
...  
2005 ◽  
Vol 72 ◽  
pp. 119-127 ◽  
Author(s):  
Tamara Golub ◽  
Caroni Pico

The interactions of cells with their environment involve regulated actin-based motility at defined positions along the cell surface. Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes, and have been implicated in most signalling processes at the cell surface. Many membrane-bound components that regulate actin cytoskeleton dynamics and cell-surface motility associate with PtdIns(4,5)P2-rich lipid rafts. Although raft integrity is not required for substrate-directed cell spreading, or to initiate signalling for motility, it is a prerequisite for sustained and organized motility. Plasmalemmal rafts redistribute rapidly in response to signals, triggering motility. This process involves the removal of rafts from sites that are not interacting with the substrate, apparently through endocytosis, and a local accumulation at sites of integrin-mediated substrate interactions. PtdIns(4,5)P2-rich lipid rafts can assemble into patches in a process depending on PtdIns(4,5)P2, Cdc42 (cell-division control 42), N-WASP (neural Wiskott-Aldrich syndrome protein) and actin cytoskeleton dynamics. The raft patches are sites of signal-induced actin assembly, and their accumulation locally promotes sustained motility. The patches capture microtubules, which promote patch clustering through PKA (protein kinase A), to steer motility. Raft accumulation at the cell surface, and its coupling to motility are influenced greatly by the expression of intrinsic raft-associated components that associate with the cytosolic leaflet of lipid rafts. Among them, GAP43 (growth-associated protein 43)-like proteins interact with PtdIns(4,5)P2 in a Ca2+/calmodulin and PKC (protein kinase C)-regulated manner, and function as intrinsic determinants of motility and anatomical plasticity. Plasmalemmal PtdIns(4,5)P2-rich raft assemblies thus provide powerful organizational principles for tight spatial and temporal control of signalling in motility.


Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 505-P ◽  
Author(s):  
YOSUKE NAGAI ◽  
DAIJI KAWANAMI ◽  
KEIICHIRO MATOBA ◽  
YUSUKE TAKEDA ◽  
KAZUNORI UTSUNOMIYA

2020 ◽  
Vol 102 (21) ◽  
Author(s):  
Yoichi Shiota ◽  
Ryusuke Hisatomi ◽  
Takahiro Moriyama ◽  
Teruo Ono

2007 ◽  
Vol 27 (52) ◽  
pp. 14448-14458 ◽  
Author(s):  
J. Lavaur ◽  
F. Bernard ◽  
P. Trifilieff ◽  
V. Pascoli ◽  
V. Kappes ◽  
...  

Cell Division ◽  
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ming-Hong Sun ◽  
Lin-Lin Hu ◽  
Chao-Ying Zhao ◽  
Xiang Lu ◽  
Yan-Ping Ren ◽  
...  

Abstract Background Ral family is a member of Ras-like GTPase superfamily, which includes RalA and RalB. RalA/B play important roles in many cell biological functions, including cytoskeleton dynamics, cell division, membrane transport, gene expression and signal transduction. However, whether RalA/B involve into the mammalian oocyte meiosis is still unclear. This study aimed to explore the roles of RalA/B during mouse oocyte maturation. Results Our results showed that RalA/B expressed at all stages of oocyte maturation, and they were enriched at the spindle periphery area after meiosis resumption. The injection of RalA/B siRNAs into the oocytes significantly disturbed the polar body extrusion, indicating the essential roles of RalA/B for oocyte maturation. We observed that in the RalA/B knockdown oocytes the actin filament fluorescence intensity was significantly increased at the both cortex and cytoplasm, and the chromosomes were failed to locate near the cortex, indicating that RalA/B regulate actin dynamics for spindle migration in mouse oocytes. Moreover, we also found that the Golgi apparatus distribution at the spindle periphery was disturbed after RalA/B depletion. Conclusions In summary, our results indicated that RalA/B affect actin dynamics for chromosome positioning and Golgi apparatus distribution in mouse oocytes.


Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 32
Author(s):  
J. R. Nascimento ◽  
A. Yu. Petrov ◽  
A. R. Vieira

In this paper, we obtain dispersion relations corresponding to plane wave solutions in Lorentz-breaking extensions of gravity with dimension 3, 4, 5 and 6 operators. We demonstrate that these dispersion relations display a usual Lorentz-invariant mode when the corresponding additive term involves higher derivatives.


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