scholarly journals Cortactin Associates with the Cell-Cell Junction Protein ZO-1 in bothDrosophilaand Mouse

1998 ◽  
Vol 273 (45) ◽  
pp. 29672-29677 ◽  
Author(s):  
Takanori Katsube ◽  
Manabu Takahisa ◽  
Ryu Ueda ◽  
Naoko Hashimoto ◽  
Mieko Kobayashi ◽  
...  
2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Shan-Shan Zhang ◽  
SoonGweon Hong ◽  
Luke P Lee ◽  
Robin M Shaw

Connexin 43 (Cx43) gap junctions (GJs) electrically couple ventricular cardiomyocytes at the intercalated disc (ID), orchestrating organized organ level contraction with each heartbeat. Disease-related disruption of the Cx43 cytoskeletal trafficking machinery is associated with mislocalization of the Cx43 gap junction protein away from the ID and lethal arrhythmias. We recently found that the majority of intracellular Cx43 cargo is associated with actin, not microtubules, and is either paused or moving slowly. It is not understood why actin is involved in Cx43 trafficking. Using micropatterned HeLa cell pairs and whole-cell automated single particle tracking algorithms, we detected that distinct actin polarity exists in the cell, including highly oriented long fibers associated with fast-moving Cx43 cargo aligned toward actively forming GJ plaques. F-actin disruption with latrunculin A (LatA) leads to a loss of Cx43 cargo directionality toward the cell-cell border, as well as a marked decrease in overall microtubule length. We also found a LatA-dependent biochemical interaction between β-actin and the microtubule plus-end-binding protein EB1, which leads growing microtubules and is a necessary component of the Cx43 forward trafficking machinery. In live cell pairs, F-actin disruption resulted in a decrease in overall EB1 activity and in the number of fully extended microtubules that reach the cell-cell border. Together, these results indicate that actin contributes to the specificity of Cx43 delivery by directing EB1-based microtubule growth toward the cell-cell junction (Please refer to attached diagram).


1998 ◽  
Vol 72 (11) ◽  
pp. 8933-8942 ◽  
Author(s):  
Kevin S. Dingwell ◽  
David C. Johnson

ABSTRACT The herpes simplex virus (HSV) glycoprotein complex gE-gI mediates the spread of viruses between adjacent cells, and this property is especially evident for cells that form extensive cell junctions, e.g., epithelial cells, fibroblasts, and neurons. Mutants lacking gE or gI are not compromised in their ability to enter cells as extracellular viruses. Therefore, gE-gI functions specifically in the movement of virus across cell-cell contacts and, as such, provides a molecular handle on this poorly understood process. We expressed gE-gI in human epithelial cells by using replication-defective adenovirus (Ad) vectors. gE-gI accumulated at lateral surfaces of the epithelial cells, colocalizing with the adherens junction protein β-catenin but was not found on either the apical or basal plasma membranes and did not colocalize with ZO-1, a component of tight junctions. In subconfluent monolayers, gE-gI was found at cell junctions but was absent from those lateral surfaces not in contact with another cell, as was the case for β-catenin. Similar localization of gE-gI to cell junctions was observed in HSV-infected epithelial cells. By contrast, HSV glycoprotein gD, expressed using a recombinant Ad vectors, was found primarily along the apical surfaces of cells, with little or no protein found on the basal or lateral surfaces. Expression of gE-gI without other HSV polypeptides did not cause redistribution of either ZO-1 or β-catenin or alter tight-junction functions. Together these results support a model in which gE-gI accumulates at sites of cell-cell contact by interacting with junctional components. We hypothesize that gE-gI mediates transfer of HSV across cell junctions by virtue of these interactions with cell junction components.


2021 ◽  
Vol 134 (21) ◽  
Author(s):  
Claudia G. Vasquez ◽  
Eva L. de la Serna ◽  
Alexander R. Dunn

ABSTRACT Polarized epithelia define a topological inside and outside, and hence constitute a key evolutionary innovation that enabled the construction of complex multicellular animal life. Over time, this basic function has been elaborated upon to yield the complex architectures of many of the organs that make up the human body. The two processes necessary to yield a polarized epithelium, namely regulated adhesion between cells and the definition of the apicobasal (top–bottom) axis, have likewise undergone extensive evolutionary elaboration, resulting in multiple sophisticated protein complexes that contribute to both functions. Understanding how these components function in combination to yield the basic architecture of a polarized cell–cell junction remains a major challenge. In this Review, we introduce the main components of apicobasal polarity and cell–cell adhesion complexes, and outline what is known about their regulation and assembly in epithelia. In addition, we highlight studies that investigate the interdependence between these two networks. We conclude with an overview of strategies to address the largest and arguably most fundamental unresolved question in the field, namely how a polarized junction arises as the sum of its molecular parts.


2005 ◽  
Vol 16 (2) ◽  
pp. 550-561 ◽  
Author(s):  
Hanane Khoury ◽  
Monica A. Naujokas ◽  
Dongmei Zuo ◽  
Veena Sangwan ◽  
Melanie M. Frigault ◽  
...  

Activation of the hepatocyte growth factor receptor Met induces a morphogenic response and stimulates the formation of branching tubules by Madin-Darby canine kidney (MDCK) epithelial cells in three-dimensional cultures. A constitutively activated ErbB2/Neu receptor, NeuNT, promotes a similar invasive morphogenic program in MDCK cells. Because both receptors are expressed in breast epithelia, are associated with poor prognosis, and hepatocyte growth factor (HGF) is expressed in stroma, we examined the consequence of cooperation between these signals. We show that HGF disrupts NeuNT-induced epithelial morphogenesis, stimulating the breakdown of cell-cell junctions, dispersal, and invasion of single cells. This correlates with a decrease in junctional proteins claudin-1 and E-cadherin, in addition to the internalization of the tight junction protein ZO-1. HGF-induced invasion of NT-expressing cells is abrogated by pretreatment with a pharmacological inhibitor of the mitogen-activated protein kinase kinase (MEK) pathway, which restores E-cadherin and ZO-1 at cell-cell junctions, establishing the involvement of MEK-dependent pathways in this process. These results demonstrate that physiological signals downstream from the HGF/Met receptor synergize with ErbB2/Neu to enhance the malignant phenotype, promoting the breakdown of cell-cell junctions and enhanced cell invasion. This is particularly important for cancers where ErbB2/Neu is overexpressed and HGF is a physiological growth factor found in the stroma.


Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 155
Author(s):  
Vanda Gaonac’h-Lovejoy ◽  
Cécile Boscher ◽  
Chantal Delisle ◽  
Jean-Philippe Gratton

Angiopoietin-1 (Ang-1) is an important proangiogenic factor also involved in the maintenance of endothelial-barrier integrity. The small GTPase Rap1 is involved in the regulation of adherens junctions through VE-cadherin-mediated adhesion, and in endothelial permeability. While many studies established that Rap1 activation is critical for endothelial cell–cell adhesions, its roles in the antipermeability effects of Ang-1 are ill-defined. Thus, we determined the contribution of Rap1 to Ang-1-stimulated angiogenic effects on endothelial cells (ECs). We found that Rap1 is activated following Ang-1 stimulation and is required for the antipermeability effects of Ang-1 on EC monolayers. Our results also revealed that Rap1 is necessary for EC sprouting stimulated by Ang-1 but had no significant effect on Ang-1-induced EC migration and adhesion. In contrast, downregulation of VE-cadherin markedly increased the adhesiveness of ECs to the substratum, which resulted in inhibition of Ang-1-stimulated migration. These results revealed that Rap1 is central to the effects of Ang-1 at intercellular junctions of ECs, whereas VE-cadherin is also involved in the adhesion of ECs to the extracellular matrix.


2012 ◽  
Vol 422 (2) ◽  
pp. 298-304 ◽  
Author(s):  
Ling Zhang ◽  
Yoshihisa Kaizuka ◽  
Nobutaka Hanagata

2010 ◽  
Vol 299 (3) ◽  
pp. C621-C629 ◽  
Author(s):  
Benoît Melchior ◽  
John A. Frangos

Atheroprone regions of the arterial circulation are characterized by time-varying, reversing, and oscillatory wall shear stress. Several in vivo and in vitro studies have demonstrated that flow reversal (retrograde flow) is atherogenic and proinflammatory. The molecular and structural basis for the sensitivity of the endothelium to flow direction, however, has yet to be determined. It has been hypothesized that the ability to sense flow direction is dependent on the direction of inclination of the interendothelial junction. Immunostaining of the mouse aorta revealed an inclination of the cell-cell junction by 13° in direction of flow in the descending aorta where flow is unidirectional. In contrast, polygonal cells of the inner curvature where flow is disturbed did not have any preferential inclination. Using a membrane specific dye, the angle of inclination of the junction was dynamically monitored using live cell confocal microscopy in confluent human endothelial cell monolayers. Upon application of shear the junctions began inclining within minutes to a final angle of 10° in direction of flow. Retrograde flow led to a reversal of junctional inclination. Flow-induced junctional inclination was shown to be independent of the cytoskeleton or glycocalyx. Additionally, within seconds, retrograde flow led to significantly higher intracellular calcium responses than orthograde flow. Together, these results show for the first time that the endothelial intercellular junction inclination is dynamically responsive to flow direction and confers the ability to endothelial cells to rapidly sense and adapt to flow direction.


2011 ◽  
Vol 45 (2) ◽  
pp. 202-220 ◽  
Author(s):  
Eugene H. Chang ◽  
Alejandro A. Pezzulo ◽  
Joseph Zabner

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