scholarly journals Rnd3 interacts with TAO kinases and contributes to mitotic cell rounding and spindle positioning

2020 ◽  
Vol 133 (6) ◽  
pp. jcs235895
Author(s):  
Ritu Garg ◽  
Chuay-Yeng Koo ◽  
Elvira Infante ◽  
Caterina Giacomini ◽  
Anne J. Ridley ◽  
...  
Keyword(s):  
Mitotic Cell ◽  
Spindle Positioning ◽  
Cell Rounding

scholarly journals Prostate-derived Sterile 20-like Kinases (PSKs/TAOKs) Are Activated in Mitosis and Contribute to Mitotic Cell Rounding and Spindle Positioning

2011 ◽  
Vol 286 (34) ◽  
pp. 30161-30170 ◽  
Author(s):  
Rachael L. Wojtala ◽  
Ignatius A. Tavares ◽  
Penny E. Morton ◽  
Ferran Valderrama ◽  
N. Shaun B. Thomas ◽  
...  
Keyword(s):  
Mitotic Cell ◽  
Spindle Positioning ◽  
Cell Rounding

scholarly journals Inversin modulates the cortical actin network during mitosis

2013 ◽  
Vol 305 (1) ◽  
pp. C36-C47 ◽  
Author(s):  
Michael E. Werner ◽  
Heather H. Ward ◽  
Carrie L. Phillips ◽  
Caroline Miller ◽  
Vincent H. Gattone ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Cyst Formation ◽  
Mitotic Cell ◽  
Mouse Embryos ◽  
Cortical Actin ◽  
Division Plane ◽  
Spindle Positioning ◽  
Actin Organization ◽  
Cell Rounding

Mutations in inversin cause nephronophthisis type II, an autosomal recessive form of polycystic kidney disease associated with situs inversus, dilatation, and kidney cyst formation. Since cyst formation may represent a planar polarity defect, we investigated whether inversin plays a role in cell division. In developing nephrons from inv−/− mouse embryos we observed heterogeneity of nuclear size, increased cell membrane perimeters, cells with double cilia, and increased frequency of binuclear cells. Depletion of inversin by siRNA in cultured mammalian cells leads to an increase in bi- or multinucleated cells. While spindle assembly, contractile ring formation, or furrow ingression appears normal in the absence of inversin, mitotic cell rounding and the underlying rearrangement of the cortical actin cytoskeleton are perturbed. We find that inversin loss causes extensive filopodia formation in both interphase and mitotic cells. These cells also fail to round up in metaphase. The resultant spindle positioning defects lead to asymmetric division plane formation and cell division. In a cell motility assay, fibroblasts isolated from inv−/− mouse embryos migrate at half the speed of wild-type fibroblasts. Together these data suggest that inversin is a regulator of cortical actin required for cell rounding and spindle positioning during mitosis. Furthermore, cell division defects resulting from improper spindle position and perturbed actin organization contribute to altered nephron morphogenesis in the absence of inversin.

scholarly journals Chaperone-Assisted Mitotic Actin Remodeling by BAG3 and HSPB8 Involves the Deacetylase HDAC6 and Its Substrate Cortactin

2020 ◽  
Vol 22 (1) ◽  
pp. 142
Author(s):  
Carole Luthold ◽  
Alice-Anaïs Varlet ◽  
Herman Lambert ◽  
François Bordeleau ◽  
Josée N. Lavoie
Keyword(s):  
Molecular Mechanisms ◽  
Protein Quality ◽  
Spatial Dynamics ◽  
Mitotic Cell ◽  
Actin Dynamics ◽  
Spindle Orientation ◽  
Actin Remodeling ◽  
Spindle Positioning ◽  
Cell Rounding

The fidelity of actin dynamics relies on protein quality control, but the underlying molecular mechanisms are poorly defined. During mitosis, the cochaperone BCL2-associated athanogene 3 (BAG3) modulates cell rounding, cortex stability, spindle orientation, and chromosome segregation. Mitotic BAG3 shows enhanced interactions with its preferred chaperone partner HSPB8, the autophagic adaptor p62/SQSTM1, and HDAC6, a deacetylase with cytoskeletal substrates. Here, we show that depletion of BAG3, HSPB8, or p62/SQSTM1 can recapitulate the same inhibition of mitotic cell rounding. Moreover, depletion of either of these proteins also interfered with the dynamic of the subcortical actin cloud that contributes to spindle positioning. These phenotypes were corrected by drugs that limit the Arp2/3 complex or HDAC6 activity, arguing for a role for BAG3 in tuning branched actin network assembly. Mechanistically, we found that cortactin acetylation/deacetylation is mitotically regulated and is correlated with a reduced association of cortactin with HDAC6 in situ. Remarkably, BAG3 depletion hindered the mitotic decrease in cortactin–HDAC6 association. Furthermore, expression of an acetyl-mimic cortactin mutant in BAG3-depleted cells normalized mitotic cell rounding and the subcortical actin cloud organization. Together, these results reinforce a BAG3′s function for accurate mitotic actin remodeling, via tuning cortactin and HDAC6 spatial dynamics.

scholarly journals Mitotic cell rounding and epithelial thinning regulate lumen growth and shape

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Esteban Hoijman ◽  
Davide Rubbini ◽  
Julien Colombelli ◽  
Berta Alsina
Keyword(s):  
Mitotic Cell ◽  
Cell Rounding

Mitotic cell rounding accelerates epithelial invagination

Nature ◽  
2013 ◽  
Vol 494 (7435) ◽  
pp. 125-129 ◽  
Author(s):  
Takefumi Kondo ◽  
Shigeo Hayashi
Keyword(s):  
Mitotic Cell ◽  
Cell Rounding

scholarly journals The Nuclear Mitotic Apparatus (NuMA) Protein: A Key Player for Nuclear Formation, Spindle Assembly, and Spindle Positioning

2021 ◽  
Vol 9 ◽  
Author(s):  
Tomomi Kiyomitsu ◽  
Susan Boerner
Keyword(s):  
Protein A ◽  
Spindle Assembly ◽  
Mitotic Cell ◽  
Cytoplasmic Dynein ◽  
Spindle Pole ◽  
Meiotic Spindle ◽  
Cell Cortex ◽  
Mitotic Apparatus ◽  
Spindle Positioning ◽  
Nuclear Mitotic Apparatus

The nuclear mitotic apparatus (NuMA) protein is well conserved in vertebrates, and dynamically changes its subcellular localization from the interphase nucleus to the mitotic/meiotic spindle poles and the mitotic cell cortex. At these locations, NuMA acts as a key structural hub in nuclear formation, spindle assembly, and mitotic spindle positioning, respectively. To achieve its variable functions, NuMA interacts with multiple factors, including DNA, microtubules, the plasma membrane, importins, and cytoplasmic dynein. The binding of NuMA to dynein via its N-terminal domain drives spindle pole focusing and spindle positioning, while multiple interactions through its C-terminal region define its subcellular localizations and functions. In addition, NuMA can self-assemble into high-ordered structures which likely contribute to spindle positioning and nuclear formation. In this review, we summarize recent advances in NuMA’s domains, functions and regulations, with a focus on human NuMA, to understand how and why vertebrate NuMA participates in these functions in comparison with invertebrate NuMA-related proteins.

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