scholarly journals Phosphorylation of Rab11-FIP2 regulates polarity in MDCK cells

2012 ◽  
Vol 23 (12) ◽  
pp. 2302-2318 ◽  
Author(s):  
Lynne A. Lapierre ◽  
Kenya M. Avant ◽  
Cathy M. Caldwell ◽  
Asli Oztan ◽  
Gerard Apodaca ◽  
...  

The Rab11 effector Rab11-family interacting protein 2 (Rab11-FIP2) regulates transcytosis through its interactions with Rab11a and myosin Vb. Previous studies implicated Rab11-FIP2 in the establishment of polarity in Madin–Darby canine kidney (MDCK) cells through phosphorylation of Ser-227 by MARK2. Here we examine the dynamic role of Rab11-FIP2 phosphorylation on MDCK cell polarity. Endogenous Rab11-FIP2 phosphorylated on Ser-227 coalesces on vesicular plaques during the reestablishment of polarity after either monolayer wounding or calcium switch. Whereas expression of the nonphosphorylatable Rab11-FIP2(S227A) elicits a loss in lumen formation in MDCK cell cysts grown in Matrigel, the putative pseudophosphorylated Rab11-FIP2(S227E) mutant induces the formation of cysts with multiple lumens. On permeable filters, Rab11-FIP2(S227E)–expressing cells exhibit alterations in the composition of both the adherens and tight junctions. At the adherens junction, p120 catenin and K-cadherin are retained, whereas the majority of the E-cadherin is lost. Although ZO-1 is retained at the tight junction, occludin is lost and the claudin composition is altered. Of interest, the effects of Rab11-FIP2 on cellular polarity did not involve myosin Vb or Rab11a. These results indicate that Ser-227 phosphorylation of Rab11-FIP2 regulates the composition of both adherens and tight junctions and is intimately involved in the regulation of polarity in epithelial cells.

1990 ◽  
Vol 258 (5) ◽  
pp. C827-C834 ◽  
Author(s):  
A. Rothstein ◽  
E. Mack

Osmotic swelling of dissociated Madin-Darby canine kidney (MDCK) cells in NaCl medium is followed by shrinking (regulatory volume decrease, or RVD) or in KCl medium by secondary swelling. The cation ionophore gramicidin has little effect on volumes of isotonic cells but accelerates volume-activated changes in either medium. Immediately after hypotonic exposure, the membrane becomes transiently hyperpolarized followed by depolarization. The depolarization phase is diminished by the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). Swelling is also associated with an almost immediate increase in Ca2+ influx and elevation of cytoplasmic Ca2+ ([Ca2+]i) preceding RVD. In Ca2(+)-free medium, [Ca2+]i rapidly declines to a low level. Osmotic swelling, under these circumstances, is associated with a small transient increase in [Ca2+]i, but RVD or secondary swelling (in KCl) are minimal. Under these conditions, addition of gramicidin or the Ca2(+)-ionophore A23187 induces significant volume changes, although not as large as those found in the presence of Ca2+. Quinine inhibits RVD in the absence of gramicidin, but not in its presence; oligomycin C, DIDS, and trifluoperazine, on the other hand, inhibit in the presence of the ionophore. These findings suggest that in MDCK cells RVD involves activation of distinct conductive K+ and Cl- pathways which allow escape of KCl and osmotically obligated water and that activation of both pathways is associated with elevated [Ca2+]i derived largely from volume activation of a Ca2(+)-influx pathway.


2000 ◽  
Vol 278 (6) ◽  
pp. C1172-C1182 ◽  
Author(s):  
Yoshio Bando ◽  
Satoshi Ogawa ◽  
Atsushi Yamauchi ◽  
Keisuke Kuwabara ◽  
Kentaro Ozawa ◽  
...  

To assess the participation of the 150-kDa oxygen-regulated protein (ORP150) in protein transport, its function in Madin-Darby canine kidney (MDCK) cells was studied. Exposure of MDCK cells to hypoxia resulted in an increase of ORP150 antigen and increased binding of ORP150 to GP80/clusterin (80-kDa glycoprotein), a natural secretory protein in this cell line. In ORP150 antisense transformant MDCK cells, GP80 was retained within the endoplasmic reticulum after exposure to hypoxia. Metabolic labeling showed the delay of GP80 maturation in antisense transformants in hypoxia, whereas its matured form was detected in wild-type cells, indicating a role of ORP150 in protein transport, especially in hypoxia. The affinity chromatographic analysis of ORP150 suggested its ability to bind to ATP-agarose. Furthermore, the ATP hydrolysis analysis showed that ORP150 can release GP80 at a lower ATP concentration. These data indicate that ORP150 may function as a unique molecular chaperone in renal epithelial cells by facilitating protein transport/maturation in an environment where less ATP is accessible.


2004 ◽  
Vol 164 (5) ◽  
pp. 717-727 ◽  
Author(s):  
David Cohen ◽  
Patrick J. Brennwald ◽  
Enrique Rodriguez-Boulan ◽  
Anne Müsch

Epithelial differentiation involves the generation of luminal surfaces and of a noncentrosomal microtubule (MT) network aligned along the polarity axis. Columnar epithelia (e.g., kidney, intestine, and Madin-Darby canine kidney [MDCK] cells) generate apical lumina and orient MT vertically, whereas liver epithelial cells (hepatocytes and WIFB9 cells) generate lumina at cell–cell contact sites (bile canaliculi) and orient MTs horizontally. We report that knockdown or inhibition of the mammalian orthologue of Caenorhabditis elegans Par-1 (EMK1 and MARK2) during polarization of cultured MDCK and WIFB9 cells prevented development of their characteristic lumen and nonradial MT networks. Conversely, EMK1 overexpression induced the appearance of intercellular lumina and horizontal MT arrays in MDCK cells, making EMK1 the first known candidate to regulate the developmental branching decision between hepatic and columnar epithelial cells. Our experiments suggest that EMK1 primarily promotes reorganization of the MT network, consistent with the MT-regulating role of this gene product in other systems, which in turn controls lumen formation and position.


1996 ◽  
Vol 270 (1) ◽  
pp. C200-C207 ◽  
Author(s):  
E. D. Kwon ◽  
K. Zablocki ◽  
E. M. Peters ◽  
K. Y. Jung ◽  
A. Garcia-Perez ◽  
...  

The amount of glycerophosphocholine (GPC) in renal medullary cells in vivo and in cultured renal [Madin-Darby canine kidney (MDCK)] cells varies with extracellular NaCl and urea. We previously showed that this is largely due to modulation of GPC degradation catalyzed by GPC:choline phosphodiesterase (GPC: PDE). GPC also varies inversely with the levels of other compatible osmolytes, the accumulation of which is induced by high tonicity. We tested whether GPC:PDE activity and GPC degradation are affected by accumulation of compatible osmolytes other than GPC. We find that MDCK cell GPC content decreases when the cells take up betaine and/or inositol from the medium. The effect is considerably greater for cells in isosmotic or high-NaCl medium than in high-urea medium. This difference is associated with suppression of betaine and inositol accumulation with high urea. We then measured GPC:PDE activity with a novel chemiluminescent assay. Addition of inositol and/or betaine to the medium greatly increases GPC:PDE activity in cells in isosmotic or high-NaCl media, but the increase is much less in high-urea medium. The increases in GPC:PDE activity, associated with the presence of betaine, are accompanied by commensurate increases in absolute rates of endogenous GPC degradation by cells in isosmotic or high-NaCl medium. We found previously that, in MDCK cells incubated for 2 days in high-NaCl medium, the rate of GPC synthesis from phosphatidylcholine is increased, correlated with an increase in phospholipase activity. However, in the present experiments, betaine accumulation has no effect on phospholipase activity under those conditions and, thus, presumably does not affect GPC synthesis. Collectively, these data support the conclusion that betaine and/or inositol reduces GPC by increasing GPC degradation catalyzed by GPC:PDE. This mechanism enables GPC to be reciprocally regulated relative to other compatible osmolytes, thus maintaining an appropriate total osmolyte content.


2004 ◽  
Vol 50 (9) ◽  
pp. 711-718 ◽  
Author(s):  
Rafael Campos-Rodríguez ◽  
Gabriela Oliver-Aguillón ◽  
Luz M Vega-Pérez ◽  
Adriana Jarillo-Luna ◽  
Dolores Hernández-Martínez ◽  
...  

Specific anti-Acanthamoeba IgA antibodies have been detected in the serum and tears of patients and healthy individuals. However, the role of human secretory IgA antibodies in inhibiting the adherence of Acanthamoeba had not been previously investigated. Therefore, the purpose of this study was to purify secretory IgA from human colostrum and analyze its effect on the adherence of Acanthamoeba trophozoites to contact lenses and Madin–Darby canine kidney (MDCK) cells. IgA antibodies to Acanthamoeba polyphaga in colostrum of healthy women as well as in saliva and serum of healthy subjects were analyzed by ELISA and Western blot analysis. In serum, saliva, and colostrum, we detected IgA antibodies that recognized several antigens of A. polyphaga. In addition, colostrum and IgA antibodies purified from it inhibited adherence of A. polyphaga trophozoites to contact lenses and MDCK cells. These results suggest that IgA antibodies may participate in the resistance to the amoebic infection, probably by inhibiting the adherence of the trophozoites to contact lenses and corneal epithelial cells.Key words: Acanthamoeba polyphaga, free-living amoebas, colostrum, IgA.


2006 ◽  
Vol 27 (5) ◽  
pp. 1745-1757 ◽  
Author(s):  
Julio Castaño ◽  
Guiomar Solanas ◽  
David Casagolda ◽  
Imma Raurell ◽  
Patricia Villagrasa ◽  
...  

ABSTRACT p120-catenin is an adherens junction-associated protein that controls E-cadherin function and stability. p120-catenin also binds intracellular proteins, such as the small GTPase RhoA. In this paper, we identify the p120-catenin N-terminal regulatory domain as the docking site for RhoA. Moreover, we demonstrate that the binding of RhoA to p120-catenin is tightly controlled by the Src family-dependent phosphorylation of p120-catenin on tyrosine residues. The phosphorylation induced by Src and Fyn tyrosine kinases on p120-catenin induces opposite effects on RhoA binding. Fyn, by phosphorylating a residue located in the regulatory domain of p120-catenin (Tyr112), inhibits the interaction of this protein with RhoA. By contrast, the phosphorylation of Tyr217 and Tyr228 by Src promotes a better affinity of p120-catenin towards RhoA. In agreement with these biochemical data, results obtained in cell lines support the important role of these phosphorylation sites in the regulation of RhoA activity by p120-catenin. Taken together, these observations uncover a new regulatory mechanism acting on p120-catenin that contributes to the fine-tuned regulation of the RhoA pathways during specific signaling events.


2016 ◽  
Vol 311 (4) ◽  
pp. L800-L809 ◽  
Author(s):  
Yufeng Tian ◽  
Xinyong Tian ◽  
Grzegorz Gawlak ◽  
Nicolene Sarich ◽  
David B. Sacks ◽  
...  

Oxidized 1-palmitoyl-2-arachidonoyl- sn-glycero-3-phosphatidylcholine (OxPAPC) attenuates agonist-induced endothelial cell (EC) permeability and increases pulmonary endothelial barrier function via enhancement of both the peripheral actin cytoskeleton and cell junctions mediated by Rac1 and Cdc42 GTPases. This study evaluated the role for the multifunctional Rac1/Cdc42 effector and regulator, IQ domain containing GTPase-activating protein (IQGAP1), as a molecular transducer of the OxPAPC-mediated EC barrier-enhancing signal. IQGAP1 knockdown in endothelial cells by gene-specific small-interfering RNA abolished OxPAPC-induced enlargement of VE-cadherin-positive adherens junctions, suppressed peripheral accumulation of actin polymerization regulators, namely cortactin, neural Wiskott-Aldrich syndrome protein (N-WASP), and actin-related protein 3, and attenuated remodeling of the peripheral actin cytoskeleton. Inhibition of OxPAPC-induced barrier enhancement by IQGAP1 knockdown was due to suppressed Rac1 and Cdc42 activation. Expression of an IQGAP1 truncated mutant showed that the GTPase regulatory domain of IQGAP1 was essential for the OxPAPC-induced membrane localization of cortactin, adherens junction proteins VE-cadherin and p120-catenin, as well as for EC permeability response. IQGAP1 knockdown attenuated the protective effect of OxPAPC against thrombin-induced cell contraction, cell junction disruption, and EC permeability. These results demonstrate for the first time the role of IQGAP1 as a critical transducer of OxPAPC-induced Rac1/Cdc42 signaling to the actin cytoskeleton and adherens junctions, which promotes cortical cytoskeletal remodeling and EC barrier-protective effects of oxidized phospholipids.


1987 ◽  
Vol 105 (6) ◽  
pp. 2735-2743 ◽  
Author(s):  
J Urban ◽  
K Parczyk ◽  
A Leutz ◽  
M Kayne ◽  
C Kondor-Koch

The biosynthesis, processing, and apical secretion of a group of polypeptides (Kondor-Koch, C., R. Bravo, S. D. Fuller, D. Cutler, and H. Garoff. 1985. Cell. 43:297-306) are studied in MDCK cells using a specific polyclonal antiserum. These polypeptides are synthesized as a precursor protein which has an apparent Mr of 65,000 in its high mannose form. This precursor is converted into a protein with an apparent Mr of 80,000 containing complex carbohydrates and sulfate. After intracellular cleavage of the 80-kD protein, the 35-45-kD subunits are secreted as an 80-kD glycoprotein complex (gp 80) linked together by disulfide bonds. Secretion of the protein complex occurs by a constitutive pathway at the apical surface of the epithelial monolayer. Since the immediate post-translational precursor, the 65-kD protein, is hydrophilic in nature as shown by its partitioning behavior in a phase-separated Triton X-114 solution, gp 80 is segregated into the apical exocytotic pathway as a soluble molecule. The proteolytic maturation of gp 80 is blocked in the presence of chloroquine and its secretion is retarded. The 80-kD precursor is released at the apical cell surface, demonstrating that proteolytic processing is not necessary for the apical secretion of this protein. If N-glycosylation is inhibited by tunicamycin treatment the protein is secreted in equal amounts at both cell surfaces, indicating a role of the carbohydrate moieties in the vectorial transport of this protein.


1996 ◽  
Vol 271 (4) ◽  
pp. C1064-C1072 ◽  
Author(s):  
C. R. Kennedy ◽  
P. R. Proulx ◽  
R. L. Hebert

The role of cytosolic phospholipase A2 (cPLA2), phosphatidylcholine-specific phospholipase C (PC-PLC) and phospholipase D (PLD) in the bradykinin (BK)-stimulated release of arachidonic acid (AA) was examined in Madin-Darby canine kidney (MDCK) cells. Release of AA, phosphorylcholine, choline, and phosphatidic acid (PA) or the transphosphatidylation product, phosphatidylethanol, was detected after 1 min of BK stimulation. A role for PC-PLC was confirmed with D609, which reduced BK-stimulated AA by 70%. Ethanol (EtOH), which blunts PA formation, diminished BK-stimulated AA release by 50%. Together, D609 and EtOH inhibited this release almost completely. Evidence indicated that diacylglycerol and PA can enhance PLA2 activity when added to cytosol extracts. The enzyme responsible for AA release was characterized as cPLA2, since PLA2 activity assayed in cell extracts was largely inhibited by an antibody to this enzyme. The membrane fraction PLA2 activity increased significantly in BK-stimulated cells. We conclude that BK signaling in MDCK cells is mediated by the lipid products of PC-PLC and PLD, increasing cPLA2 activity, possibly by causing perturbations in the bilayer structure of its substrate, by a direct effect on the enzyme or by activation of protein kinases such as protein kinase C.


1988 ◽  
Vol 107 (1) ◽  
pp. 221-230 ◽  
Author(s):  
B B Finlay ◽  
B Gumbiner ◽  
S Falkow

Many intracellular parasites are capable of penetrating host epithelial barriers. To study this process in more detail we examined the interactions between the pathogenic bacteria Salmonella choleraesuis and polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells grown on membrane filters. Association of bacteria with the MDCK cell apical surface was an active event, requiring bacterial RNA and protein synthesis, and was blocked by low temperatures. Salmonella were internalized within a membrane-bound vacuole and exhibited penetration through, but not between MDCK cells. A maximum of 14 Salmonella per MDCK cell crossed the monolayer per hour to the basolateral surface yet the monolayer remained viable and impermeable to Escherichia coli. Apical S. choleraesuis infection resulted in an increase in paracellular permeability but the MDCK intercellular contacts were not significantly disrupted. Basolateral S. choleraesuis infection was inefficient, and only small numbers of S. choleraesuis penetrated to the apical medium.


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