Faculty Opinions recommendation of Myosin VI and vinculin cooperate during the morphogenesis of cadherin cell cell contacts in mammalian epithelial cells.

Sphingosine 1-phosphate (S1P), a bioactive phospholipid, simultaneously induces actin cytoskeletal rearrangements and activation of matriptase, a membrane-associated serine protease in human mammary epithelial cells. In this study, we used a monoclonal antibody selective for activated, two-chain matriptase to examine the functional relationship between these two S1P-induced events. Ten minutes after exposure of 184 A1N4 mammary epithelial cells to S1P, matriptase was observed to accumulate at cell-cell contacts. Activated matriptase first began to appear as small spots at cell-cell contacts, and then its deposits elongated along cell-cell contacts. Concomitantly, S1P induced assembly of adherens junctions and subcortical actin belts. Matriptase localization was observed to be coincident with markers of adherens junctions at cell-cell contacts but likely not to be incorporated into the tightly bound adhesion plaque. Disruption of subcortical actin belt formation and prevention of adherens junction assembly led to prevention of accumulation and activation of the protease at cell-cell contacts. These data suggest that S1P-induced accumulation and activation of matriptase depend on the S1P-induced adherens junction assembly. Although MAb M32, directed against one of the low-density lipoprotein receptor class A domains of matriptase, blocked S1P-induced activation of the enzyme, the antibody had no effect on S1P-induced actin cytoskeletal rearrangement. Together, these data indicate that actin cytoskeletal rearrangement is necessary but not sufficient for S1P-induced activation of matriptase at cell-cell contacts. The coupling of matriptase activation to adherens junction assembly and actin cytoskeletal rearrangement may serve to ensure tight control of matriptase activity, restricted to cell-cell junctions of mammary epithelial cells.

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Mechanisms for de novo biogenesis of an apical membrane compartment in groups of simple epithelial cells surrounded by extracellular matrix

Journal of Cell Science ◽

10.1242/jcs.110.22.2781 ◽

1997 ◽

Vol 110 (22) ◽

pp. 2781-2794 ◽

Cited By ~ 2

Author(s):

G.K. Ojakian ◽

W.J. Nelson ◽

K.A. Beck

Keyword(s):

Epithelial Cells ◽

Cell Surface ◽

Golgi Complex ◽

De Novo ◽

Apical Membrane ◽

Free Cell ◽

Cell Contacts ◽

Lateral Membrane ◽

Cell Cell

In open monolayers of epithelial cells grown in vitro, the apical membrane domain forms on the free cell surface that faces the culture medium. However, in vivo, the apical lumenal compartment arises within groups of cells that do not have a free cell surface. We designed in vitro culture conditions, using small colonies of MDCK cells overlaid with collagen, in which formation of the apical membrane must occur de novo by remodeling existing membrane domains that are contacted by other cells or extracellular matrix. Within 12 hours of collagen overlay, the apical membrane glycoprotein gp135 is removed from the free cell surface, while lateral membrane proteins (e.g. Na+,K+-ATPase) remain at sites of cell-cell contacts. Subsequently, lumenal structures, containing gp135 and the apically secreted protein gp81, formed within these cell-cell contacts. Na+,K+-ATPase, adherens junction (E-cadherin, alpha- and beta-catenins) and tight junction (ZO-1) proteins were localized on the lateral membrane adjacent to, but excluded from the gp135-positive lumenal compartment. Therefore, each lumen represents a newly formed apical compartment on the lateral membrane. The Golgi complex (alpha-mannosidase II and Golgi beta-spectrin), centrosomes (gamma-tubulin) and microtubules reorient to a cytoplasmic position adjacent to the newly-forming apical lumenal compartments. Significantly, addition of colchicine, nocodazole or brefeldin A inhibits apical lumen formation. These results demonstrate that simple epithelial cells form an apical lumenal compartment de novo through initial intermixing, and then sorting of apical and basal-lateral membrane proteins at sites of cell-cell contacts. In addition, apical lumen formation requires an intact microtubule network, microtubule-dependent reorientation of the Golgi complex and secretory apparatus, and fully functional protein delivery from the Golgi complex to the forming apical cell surface.

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Distinct Rho GTPase Activities Regulate Epithelial Cell Localization of the Adhesion Molecule CEACAM1: Involvement of the CEACAM1 Transmembrane Domain

Molecular and Cellular Biology ◽

10.1128/mcb.23.20.7291-7304.2003 ◽

2003 ◽

Vol 23 (20) ◽

pp. 7291-7304 ◽

Cited By ~ 10

Author(s):

Bénédicte Fournès ◽

Jennifer Farrah ◽

Melanie Olson ◽

Nathalie Lamarche-Vane ◽

Nicole Beauchemin

Keyword(s):

Epithelial Cell ◽

Epithelial Cells ◽

Rho Gtpases ◽

Rho Gtpase ◽

Transmembrane Domain ◽

Rho Kinase ◽

Cell Contacts ◽

Cell Localization ◽

Downstream Effector ◽

Cell Cell

ABSTRACT CEACAM1 is an intercellular adhesion glycoprotein. As CEACAM1 plays an important role in epithelial cell signaling and functions, we have examined its localization in epithelial cells. We have observed that distribution at cell contacts is not always seen in these cells, suggesting that CEACAM1 localization might be regulated. In Swiss 3T3 cells, the targeting of CEACAM1 at cell-cell boundaries is regulated by the Rho GTPases. In the present study, we have used the MDCK epithelial cells to characterize the effects of the Rho GTPases and their effectors on CEACAM1 intercellular targeting. Activated Cdc42 and Rac1 or their downstream effector PAK1 targeted CEACAM1 to sites of cell-cell contacts. On the other hand, neither activated RhoA nor activated Rho kinase directed CEACAM1 to cell boundaries, resulting in a condensed distribution of CEACAM1 at the cell surface. Interestingly, inhibition of this pathway resulted in CEACAM1 intercellular localization suggesting that a tightly regulated balance of Rho GTPase activities is necessary to target CEACAM1 at cell-cell boundaries. In addition, using CEACAM1 mutants and chimeric fusion constructs containing domains of the colony-stimulating factor receptor, we have shown that the transmembrane domain of CEACAM1 is responsible for the Cdc42-induced targeting at cell-cell contacts.

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Characterization of integrins in cultured human renal cortical tubule epithelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.1994.267.4.f612 ◽

1994 ◽

Vol 267 (4) ◽

pp. F612-F623

Author(s):

E. E. Simon ◽

C. H. Liu ◽

M. Das ◽

S. Nigam ◽

T. J. Broekelmann ◽

...

Keyword(s):

Extracellular Matrix ◽

Cell Adhesion ◽

Epithelial Cells ◽

Initial Attachment ◽

Cell Contacts ◽

Cell Matrix ◽

Beta 1 Integrin ◽

Tubule Cells ◽

Alpha V Beta 3 ◽

Cell Cell

We have characterized the integrins present on cultured tubule epithelial cells from human renal cortexes, enriched for proximal cells, using fluorescence microscopy, immunoprecipitation, and cell adhesion assays. By immunofluorescence, the alpha 3-integrin subunit stained most intensely and was present on all cells predominantly at cell-cell contacts. The alpha 6-subunit was present on all cells in a pattern consistent with extracellular matrix contacts. The alpha 5-subunit was present on most cells in a cell-matrix contact pattern; alpha V-subunit was weakly positive and occasionally seen in cell-matrix contacts. The alpha 2-subunit was present on clusters of distal tubule cells, predominantly at cell-cell contacts. Immunoprecipitation revealed the predominant integrin to be alpha 3 beta 1 with some alpha 2 beta 1, presumably contributed by distal cells. The alpha 5 beta 1-, alpha 6 beta 1-, alpha 6 beta 4-, and alpha V beta 3-integrins, as well as trace amounts of alpha 1 beta 1-integrins, were also present. The alpha 4 beta 1-integrin was not detected. Initial attachment to fibronectin was mediated by alpha V beta 3- and alpha 5 beta 1-integrins; initial attachment to laminin was mediated by the alpha 6 beta 1- and alpha 3 beta 1- integrins and, in some preparations, by an unidentified integrin; and initial attachment to collagen type IV was mediated by alpha V beta 3-integrin and an unidentified beta 1-integrin. After extensively immunodepleting membrane extracts with anti-alpha 1, -alpha 2, -alpha 3, -alpha 4, -alpha 5, -alpha 6, and -alpha V antibodies, an anti-beta 1 antibody still precipitated an integrin. Its electrophoretic mobility differs from the laminin-binding alpha 7 beta 1-integrin. Thus we have identified many of the integrins on cortical tubule cells and their role in mediating initial attachment to extracellular matrix. However, the cell adhesion assays and immunoprecipitations suggest the presence of an unidentified beta 1-integrin that may mediate renal tubule cell attachment to laminin and collagen.

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Crk-Associated Substrate p130Cas Interacts with Nephrocystin and Both Proteins Localize to Cell–Cell Contacts of Polarized Epithelial Cells

Experimental Cell Research ◽

10.1006/excr.2000.4822 ◽

2000 ◽

Vol 256 (1) ◽

pp. 168-178 ◽

Cited By ~ 65

Author(s):

John C. Donaldson ◽

Peter J. Dempsey ◽

Samyukta Reddy ◽

Amy H. Bouton ◽

Robert J. Coffey ◽

...

Keyword(s):

Epithelial Cells ◽

Cell Contacts ◽

Polarized Epithelial Cells ◽

Cell Cell

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Choroid plexus epithelial cells express the adhesion protein P-cadherin at cell-cell contacts and syntaxin-4 in the luminal membrane domain

AJP Cell Physiology ◽

10.1152/ajpcell.00305.2017 ◽

2018 ◽

Vol 314 (5) ◽

pp. C519-C533 ◽

Cited By ~ 5

Author(s):

Inga Baasch Christensen ◽

Esben Nees Mogensen ◽

Helle Hasager Damkier ◽

Jeppe Praetorius

Keyword(s):

Plasma Membrane ◽

Epithelial Cells ◽

Choroid Plexus ◽

Basolateral Membrane ◽

Membrane Domain ◽

Cell Contacts ◽

Luminal Membrane ◽

Syntaxin 4 ◽

Choroid Plexus Epithelial ◽

Cell Cell

The choroid plexus epithelial cells (CPECs) belong to a small group of polarized cells, where the Na+-K+-ATPase is expressed in the luminal membrane. The basic polarity of the cells is, therefore, still debated. We investigated the subcellular distribution of an array of proteins known to play fundamental roles either in establishing and maintaining basic cell polarity or in the polarized delivery and recycling of plasma membrane proteins. Immunofluorescence histochemical analysis was applied to determine the subcellular localization of apical and basolateral membrane determinants. Mass spectrometry analysis of CPECs isolated by fluorescence-activated cell sorting was applied to determine the expression of specific forms of the proteins. CPECs mainly express the cell-adhesive P-cadherin, which is localized to the lateral membranes. Proteins belonging to the Crumbs and partitioning defective (Par) protein complexes were all localized to the luminal membrane domain. Par-1 and the Scribble complex were localized to the basolateral membrane domain. Lethal(2) giant larvae homolog 2 (Lgl2) labeling was preferentially observed in the luminal membrane domain. Phosphatidylinositol 3,4,5-trisphosphate (PIP3) was immunolocalized to the basolateral membrane domain, while phosphatidylinositol 4,5-bisphosphate (PIP2) staining was most prominent in the luminal membrane domain along with the PIP3 phosphatase, Pten. The apical target-SNARE syntaxin-3 and the basolateral target-SNARE syntaxin-4 were both localized to the apical membrane domain in CPECs, which lack cellular expression of the clathrin adaptor protein AP-1B for basolateral protein recycling. In conclusion, the CPECs are conventionally polarized, but express P-cadherin at cell-cell contacts, and Lgl2 and syntaxin-4 in the luminal plasma membrane domain.

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