scholarly journals Modulating apical–basal polarity by building and deconstructing a Yurt

2018 ◽  
Vol 217 (11) ◽  
pp. 3772-3773 ◽  
Author(s):  
Kia Z. Perez-Vale ◽  
Mark Peifer
Keyword(s):  
Cell Polarity ◽  
Protein Networks ◽  
Cell Biol ◽  
Antagonistic Interactions

Cell polarity is regulated by protein networks in the apical and basolateral domains that repress one another by mutually antagonistic interactions. Gamblin et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201803099) reveal that apical Crumbs is antagonized by oligomerization of basolateral Yurt, while Yurt oligomerization is in turn negatively regulated by the apical kinase aPKC.

scholarly journals Move your microvilli

2014 ◽  
Vol 207 (1) ◽  
pp. 9-11 ◽  
Author(s):  
Robert S. Fischer
Keyword(s):  
Wound Healing ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Polarity ◽  
Apical Membrane ◽  
Apical Surface ◽  
Epithelial Cell Polarity ◽  
Cell Biol ◽  
Polarized Epithelial Cells

Polarized epithelial cells create tightly packed arrays of microvilli in their apical membrane, but the fate of these microvilli is relatively unknown when epithelial cell polarity is lost during wound healing. In this issue, Klingner et al. (2014. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201402037) show that, when epithelial cells become subconfluent, actomyosin contractions locally within the apical cortex cause their microvilli to become motile over the dorsal/apical surface. Their unexpected observations may have implications for epithelial responses in wound healing and disease.

scholarly journals Do migrating cells need a nucleus?

2018 ◽  
Vol 217 (3) ◽  
pp. 799-801 ◽  
Author(s):  
Rhoda J. Hawkins
Keyword(s):  
Cell Polarity ◽  
Three Dimensions ◽  
Mechanical Responses ◽  
Cell Biol ◽  
And Migration ◽  
Migrating Cells

How the nucleus affects cell polarity and migration is unclear. In this issue, Graham et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201706097) show that enucleated cells polarize and migrate in two but not three dimensions and propose that the nucleus is a necessary component of the molecular clutch regulating normal mechanical responses.

scholarly journals A small part of myosin IIB takes on a big role in cell polarity

2015 ◽  
Vol 209 (1) ◽  
pp. 11-12 ◽  
Author(s):  
Aidan M. Fenix ◽  
Dylan T. Burnette
Keyword(s):  
Cell Migration ◽  
Cell Polarity ◽  
Nonmuscle Myosin ◽  
New Paradigm ◽  
Cell Biol ◽  
Directional Cell Migration

A migrating cell must establish front-to-back polarity in order to move. In this issue, Juanes-Garcia et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201407059) report that a short serine-rich motif in nonmuscle myosin IIB is required to establish the cell’s rear. This motif represents a new paradigm for what determines directional cell migration.

scholarly journals DLG5 connects cell polarity and Hippo signaling protein networks by linking PAR-1 with MST1/2

2016 ◽  
Vol 30 (24) ◽  
pp. 2696-2709 ◽  
Author(s):  
Julian Kwan ◽  
Anna Sczaniecka ◽  
Emad Heidary Arash ◽  
Liem Nguyen ◽  
Chia-Chun Chen ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Protein Networks ◽  
Hippo Signaling ◽  
Signaling Protein

scholarly journals Regulating polarity by directing traffic: Cdc42 prevents adherens junctions from Crumblin' aPart

2008 ◽  
Vol 183 (6) ◽  
pp. 971-974 ◽  
Author(s):  
Mara C. Duncan ◽  
Mark Peifer
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Cell Polarity ◽  
Adherens Junctions ◽  
Vesicular Trafficking ◽  
Cell Junction ◽  
Par Proteins ◽  
Cell Biol ◽  
Embryonic Morphogenesis ◽  
Junction Proteins

The GTPase Cdc42 was among the original genes identified with roles in cell polarity, and interest in its cellular roles from yeast to humans remains high. Cdc42 is a well-known regulator of the actin cytoskeleton, but also plays important roles in vesicular trafficking. In this issue, Harris and Tepass (Harris, K.P, and U. Tepass. 2008. J. Cell. Biol. 183:1129–1143) provide new insights into how Cdc42 and Par proteins work together to modulate cell adhesion and polarity during embryonic morphogenesis by regulating the traffic of key cell junction proteins.

scholarly journals Rab-mediated membrane trafficking and the control of epithelial cell polarity

2016 ◽  
Vol 213 (3) ◽  
pp. 301-303 ◽  
Author(s):  
Maria S. Ioannou ◽  
Peter S. McPherson
Keyword(s):  
Epithelial Cell ◽  
Cell Polarity ◽  
Membrane Trafficking ◽  
Three Dimensional ◽  
Model Systems ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Epithelial Cell Polarity ◽  
Cell Biol ◽  
Apical Trafficking

Development of cell polarity requires apical trafficking of podocalyxin; yet the regulation of its transport is unclear. In this issue, Mrozowska and Fukuda (2016. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201512024) demonstrate that different sets of Rabs and Rab effectors are used to regulate podocalyxin trafficking in two- versus three-dimensional model systems.

scholarly journals Opposing Roles for Actin in Cdc42p Polarization

2005 ◽  
Vol 16 (3) ◽  
pp. 1296-1304 ◽  
Author(s):  
Javier E. Irazoqui ◽  
Audrey S. Howell ◽  
Chandra L. Theesfeld ◽  
Daniel J. Lew
Keyword(s):  
Actin Cytoskeleton ◽  
Cell Polarity ◽  
Budding Yeast ◽  
Cortical Actin ◽  
Independent Manner ◽  
Actin Depolymerization ◽  
Cell Biol ◽  
Actin Cables ◽  
Unexpected Difference

In animal and fungal cells, the monomeric GTPase Cdc42p is a key regulator of cell polarity that itself exhibits a polarized distribution in asymmetric cells. Previous work showed that in budding yeast, Cdc42p polarization is unaffected by depolymerization of the actin cytoskeleton (Ayscough et al., J. Cell Biol. 137, 399–416, 1997). Surprisingly, we now report that unlike complete actin depolymerization, partial actin depolymerization leads to the dispersal of Cdc42p from the polarization site in unbudded cells. We provide evidence that dispersal is due to endocytosis associated with cortical actin patches and that actin cables are required to counteract the dispersal and maintain Cdc42p polarity. Thus, although Cdc42p is initially polarized in an actin-independent manner, maintaining that polarity may involve a reinforcing feedback between Cdc42p and polarized actin cables to counteract the dispersing effects of actin-dependent endocytosis. In addition, we report that once a bud has formed, polarized Cdc42p becomes more resistant to dispersal, revealing an unexpected difference between unbudded and budded cells in the organization of the polarization site.

scholarly journals SNAP to attention: A SNARE complex regulates neuronal progenitor polarity

2020 ◽  
Vol 220 (1) ◽  
Author(s):  
Victor Tarabykin
Keyword(s):  
Cell Polarity ◽  
Radial Glia ◽  
Snare Complex ◽  
Membrane Targeting ◽  
Neuronal Progenitor ◽  
Neuronal Progenitors ◽  
Cell Biol ◽  
Polarity Establishment ◽  
Adherence Junction

SNARE vesicle targeting complex controls the polarity of neuronal progenitors. Kunii et al. (2020. J. Cell Biol. https://doi.org/10.1083/jcb.201910080) show that the SNAP23–VAMP8–Syntaxin1B complex is required for membrane targeting of N-cadherin and formation of adherence junction complexes in radial glia neuronal progenitors, the major prerequisite of cell polarity establishment.

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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