scholarly journals The periciliary ring in polarized epithelial cells is a hot spot for delivery of the apical protein gp135

2015 ◽  
Vol 211 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Emily H. Stoops ◽  
Michael Hull ◽  
Christina Olesen ◽  
Kavita Mistry ◽  
Jennifer L. Harder ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Primary Cilium ◽  
Protein Delivery ◽  
Hot Spot ◽  
Basolateral Membrane ◽  
Protein A ◽  
Surface Proteins ◽  
Apical Surface ◽  
Directed Movement ◽  
Polarized Epithelial Cells

In polarized epithelial cells, newly synthesized cell surface proteins travel in carrier vesicles from the trans Golgi network to the apical or basolateral plasma membrane. Despite extensive research on polarized trafficking, the sites of protein delivery are not fully characterized. Here we use the SNAP tag system to examine the site of delivery of the apical glycoprotein gp135. We show that a cohort of gp135 is delivered to a ring surrounding the base of the primary cilium, followed by microtubule-dependent radial movement away from the cilium. Delivery to the periciliary ring was specific to newly synthesized and not recycling protein. A subset of this newly delivered protein traverses the basolateral membrane en route to the apical membrane. Crumbs3a, another apical protein, was not delivered to the periciliary region, instead making its initial apical appearance in a pattern that resembled its steady-state distribution. Our results demonstrate a surprising “hot spot” for gp135 protein delivery at the base of the primary cilium and suggest the existence of a novel microtubule-based directed movement of a subset of apical surface proteins.

scholarly journals Par3 functions in the biogenesis of the primary cilium in polarized epithelial cells

2007 ◽  
Vol 179 (6) ◽  
pp. 1133-1140 ◽  
Author(s):  
Jeff Sfakianos ◽  
Akashi Togawa ◽  
Sandra Maday ◽  
Mike Hull ◽  
Marc Pypaert ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Primary Cilium ◽  
Basolateral Membrane ◽  
Intraflagellar Transport ◽  
Binding Motif ◽  
Apical Surface ◽  
Anterograde Transport ◽  
Ciliary Membrane ◽  
Microtubule Motor ◽  
Dependent Transport

Par3 is a PDZ protein important for the formation of junctional complexes in epithelial cells. We have identified an additional role for Par3 in membrane biogenesis. Although Par3 was not required for maintaining polarized apical or basolateral membrane domains, at the apical surface, Par3 was absolutely essential for the growth and elongation of the primary cilium. The activity reflected its ability to interact with kinesin-2, the microtubule motor responsible for anterograde transport of intraflagellar transport particles to the tip of the growing cilium. The Par3 binding partners Par6 and atypical protein kinase C interacted with the ciliary membrane component Crumbs3 and we show that the PDZ binding motif of Crumbs3 was necessary for its targeting to the ciliary membrane. Thus, the Par complex likely serves as an adaptor that couples the vectorial movement of at least a subset of membrane proteins to microtubule-dependent transport during ciliogenesis.

scholarly journals A CD317/tetherin–RICH2 complex plays a critical role in the organization of the subapical actin cytoskeleton in polarized epithelial cells

2009 ◽  
Vol 184 (5) ◽  
pp. 721-736 ◽  
Author(s):  
Ruth Rollason ◽  
Viktor Korolchuk ◽  
Clare Hamilton ◽  
Mark Jepson ◽  
George Banting
Keyword(s):  
Epithelial Cells ◽  
Actin Cytoskeleton ◽  
Transmembrane Domain ◽  
Basolateral Membrane ◽  
Critical Role ◽  
Integral Membrane Protein ◽  
Apical Surface ◽  
Actin Network ◽  
Cell Height ◽  
Polarized Epithelial Cells

CD317/tetherin is a lipid raft–associated integral membrane protein with a novel topology. It has a short N-terminal cytosolic domain, a conventional transmembrane domain, and a C-terminal glycosyl-phosphatidylinositol anchor. We now show that CD317 is expressed at the apical surface of polarized epithelial cells, where it interacts indirectly with the underlying actin cytoskeleton. CD317 is linked to the apical actin network via the proteins RICH2, EBP50, and ezrin. Knocking down expression of either CD317 or RICH2 gives rise to the same phenotype: a loss of the apical actin network with concomitant loss of apical microvilli, an increase in actin bundles at the basal surface, and a reduction in cell height without any loss of tight junctions, transepithelial resistance, or the polarized targeting of apical and basolateral membrane proteins. Thus, CD317 provides a physical link between lipid rafts and the apical actin network in polarized epithelial cells and is crucial for the maintenance of microvilli in such cells.

scholarly journals A protein targeting signal that functions in polarized epithelial cells in vivo

1996 ◽  
Vol 315 (3) ◽  
pp. 857-862 ◽  
Author(s):  
Simi ALI ◽  
Judith HALL ◽  
Geoffrey P. HAZLEWOOD ◽  
Barry H. HIRST ◽  
Harry J. GILBERT
Keyword(s):  
Epithelial Cells ◽  
Mammalian Cells ◽  
Basolateral Membrane ◽  
Apical Surface ◽  
Reporter Protein ◽  
Gpi Anchor ◽  
Targeting Signal ◽  
Polarized Epithelial Cells ◽  
Anchor Sequence

Eukaryotic membrane-associated polypeptides often contain a glycosylphosphatidylinositol (GPI) anchor that signals the attachment of GPI lipids to these proteins. The GPI anchor can function as a basolateral or apical targeting signal in mammalian cells cultured in vitro, although the function of the GPI anchor in vivo remains to be elucidated. In this study we have evaluated the effect of fusing a GPI anchor sequence to a prokaryotic reporter protein on the cellular location of the polypeptide in polarized epithelial cells of transgenic mice. The bacterial enzyme, when fused to a eukaryotic signal peptide, was secreted through the basolateral membrane of small-intestinal enterocytes; however, when the enzyme was linked to the GPI anchor sequence the polypeptide was redirected to the apical surface of the epithelial cells. These data provide the first direct evidence that the GPI anchor functions as an apical membrane protein sorting signal in polarized epithelial cells in vivo.

scholarly journals Multi-dimensional and spatiotemporal correlative imaging at the plasma membrane of live cells to determine the continuum nano-to-micro scale lipid adaptation and collective motion

2021 ◽  
Author(s):  
Miguel Bernabé-Rubio ◽  
Minerva Bosch-Fortea ◽  
Miguel A. Alonso ◽  
Jorge Bernardino de la Serna
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Primary Cilium ◽  
Cell Biology ◽  
Spatial Scales ◽  
Apical Surface ◽  
Ciliary Membrane ◽  
Correlative Imaging ◽  
Polarized Epithelial Cells ◽  
Membrane Patch

AbstractThe primary cilium is a specialized plasma membrane protrusion with important receptors for signalling pathways. In polarized epithelial cells, the primary cilium assembles after the midbody remnant (MBR) encounters the centrosome at the apical surface. The membrane surrounding the MBR, namely remnant associated membrane patch (RAMP) once situated next to the centrosome, releases some of its lipid components to form a centrosome-associated membrane patch (CAMP) from which the ciliary membrane stems. The RAMP undergoes a spatiotemporal membrane refinement during the formation of the CAMP, which becomes highly enriched in condensed membranes with low lateral mobility. To better understand this process, we have developed a correlative imaging approach that yields quantitative information about the lipid lateral packing, its mobility and collective assembly at the plasma membrane at different spatial scales over time. Our work paves the way towards a quantitative understanding of lipid collective assembly at the plasma membrane spatiotemporally as a functional determinant in cell biology and its direct correlation with the membrane physicochemical state. These findings allowed us to gain a deeper insight into the mechanisms behind the biogenesis of the ciliary membrane of polarized epithelial cells.

scholarly journals Sorting of Marburg Virus Surface Protein and Virus Release Take Place at Opposite Surfaces of Infected Polarized Epithelial Cells

2001 ◽  
Vol 75 (3) ◽  
pp. 1274-1283 ◽  
Author(s):  
Christian Sänger ◽  
Elke Mühlberger ◽  
Elena Ryabchikova ◽  
Larissa Kolesnikova ◽  
Hans-Dieter Klenk ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Surface Protein ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Virus Surface ◽  
Mdckii Cells ◽  
Vesicular Stomatitis ◽  
Polarized Epithelial Cells

ABSTRACT Marburg virus, a filovirus, causes severe hemorrhagic fever with hitherto poorly understood molecular pathogenesis. We have investigated here the vectorial transport of the surface protein GP of Marburg virus in polarized epithelial cells. To this end, we established an MDCKII cell line that was able to express GP permanently (MDCK-GP). The functional integrity of GP expressed in these cells was analyzed using vesicular stomatitis virus pseudotypes. Further experiments revealed that GP is transported in MDCK-GP cells mainly to the apical membrane and is released exclusively into the culture medium facing the apical membrane. When MDCKII cells were infected with Marburg virus, the majority of GP was also transported to the apical membrane, suggesting that the protein contains an autonomous apical transport signal. Release of infectious progeny virions, however, took place exclusively at the basolateral membrane of the cells. Thus, vectorial budding of Marburg virus is presumably determined by factors other than the surface protein.

Epithelial sorting of a glycosylphosphatidylinositol-anchored bacterial protein expressed in polarized renal MDCK and intestinal Caco-2 cells

1995 ◽  
Vol 108 (1) ◽  
pp. 369-377 ◽  
Author(s):  
K.L. Soole ◽  
M.A. Jepson ◽  
G.P. Hazlewood ◽  
H.J. Gilbert ◽  
B.H. Hirst
Keyword(s):  
Epithelial Cells ◽  
Cell Surface ◽  
Intestinal Epithelial Cells ◽  
Mdck Cells ◽  
Basolateral Membrane ◽  
Apical Cell ◽  
Apical Surface ◽  
Intestinal Epithelial ◽  
Gpi Anchor ◽  
Sorting Signal

To evaluate whether a glycosylphosphatidylinositol (GPI) anchor can function as a protein sorting signal in polarized intestinal epithelial cells, the GPI-attachment sequence from Thy-1 was fused to bacterial endoglucanase E' (EGE') from Clostridium thermocellum and polarity of secretion of the chimeric EGE'-GPI protein was evaluated. The chimeric EGE'-GPI protein was shown to be associated with a GPI anchor by TX-114 phase-partitioning and susceptibility to phosphoinositol-specific phospholipase C. In polarized MDCK cells, EGE' was localized almost exclusively to the apical cell surface, while in polarized intestinal Caco-2 cells, although 80% of the extracellular form of the enzyme was routed through the apical membrane over a 24 hour period, EGE' was also detected at the basolateral membrane. Rates of delivery of EGE'-GPI to the two membrane domains in Caco-2 cells, as determined with a biotinylation protocol, revealed apical delivery was approximately 2.5 times that of basolateral. EGE' delivered to the basolateral cell surface was transcytosed to the apical surface. These data indicate that a GPI anchor does represent a dominant apical sorting signal in intestinal epithelial cells. However, the mis-sorting of a proportion of EGE'GPI to the basolateral surface of Caco-2 cells provides an explanation for additional sorting signals in the ectodomain of some endogenous GPI-anchored proteins.

Membrane receptor location defines receptor interaction with signaling proteins in a polarized epithelium

1999 ◽  
Vol 276 (1) ◽  
pp. C91-C101 ◽  
Author(s):  
Kurt Amsler ◽  
Scott K. Kuwada
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Tyrosine Phosphorylation ◽  
Basolateral Membrane ◽  
Growth Factor Receptor ◽  
Membrane Receptor ◽  
Membrane Receptors ◽  
Receptor Interaction ◽  
Signaling Proteins ◽  
Polarized Epithelial Cells

Signal transduction from receptors is mediated by the interaction of activated receptors with proximate downstream signaling proteins. In polarized epithelial cells, the membrane is divided into subdomains: the apical and basolateral membranes. Membrane receptors may be present in one or both subdomains. Using a combination of immunoprecipitation and Western blot analyses, we tested the hypothesis that a tyrosine kinase growth factor receptor, epidermal growth factor receptor (EGFR), interacts with distinct signaling proteins when present at the apical vs. basolateral membrane of a polarized renal epithelial cell. We report here that tyrosine phosphorylation of phospholipase C-γ (PLC-γ) was induced only when basolateral EGFR was activated. In contrast, tyrosine phosphorylation of several other signaling proteins was increased by activation of receptor at either surface. All signaling proteins were distributed diffusely throughout the cytoplasm; however, PLC-γ protein also displayed a concentration at lateral cell borders. These results demonstrate that in polarized epithelial cells the array of signaling pathways initiated by activation of a membrane receptor is defined, at least in part, by the membrane location of the receptor.

scholarly journals Mumps Virus Is Released from the Apical Surface of Polarized Epithelial Cells, and the Release Is Facilitated by a Rab11-Mediated Transport System

2015 ◽  
Vol 89 (23) ◽  
pp. 12026-12034 ◽  
Author(s):  
Hiroshi Katoh ◽  
Yuichiro Nakatsu ◽  
Toru Kubota ◽  
Masafumi Sakata ◽  
Makoto Takeda ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Measles Virus ◽  
Intracellular Transport ◽  
Systemic Infection ◽  
Mumps Virus ◽  
Progeny Virus ◽  
Apical Surface ◽  
Virus Release ◽  
Polarized Cells ◽  
Polarized Epithelial Cells

ABSTRACTMumps virus (MuV) is an airborne virus that causes a systemic infection in patients.In vivo, the epithelium is a major replication site of MuV, and thus, the mode of MuV infection of epithelial cells is a subject of interest. Our data in the present study showed that MuV entered polarized epithelial cells via both the apical and basolateral surfaces, while progeny viruses were predominantly released from the apical surface. In polarized cells, intracellular transport of viral ribonucleoprotein (vRNP) complexes was dependent on Rab11-positive endosomes, and vRNP complexes were transported to the apical membrane. Expression of a dominant negative form of Rab11 (Rab11S25N) reduced the progeny virus release in polarized cells but not in nonpolarized cells. Although in this way these effects were correlated with cell polarity, Rab11S25N did not modulate the direction of virus release from the apical surface. Therefore, our data suggested that Rab11 is not a regulator of selective apical release of MuV, although it acts as an activator of virus release from polarized epithelial cells. In addition, our data and previous studies on Sendai virus, respiratory syncytial virus, and measles virus suggested that selective apical release from epithelial cells is used by many paramyxoviruses, even though they cause either a systemic infection or a local respiratory infection.IMPORTANCEMumps virus (MuV) is the etiological agent of mumps and causes a systemic infection. However, the precise mechanism by which MuV breaks through the epithelial barriers and achieves a systemic infection remains unclear. In the present study, we show that the entry of MuV is bipolar, while the release is predominantly from the apical surface in polarized epithelial cells. In addition, the release of progeny virus was facilitated by a Rab11-positive recycling endosome and microtubule network. Our data provide important insights into the mechanism of transmission and pathogenesis of MuV.

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.

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