Lipid Polarity Is Maintained in Absence of Tight Junctions

Ikenouchi, Junichi; Suzuki, Mayu; Umeda, Kazuaki; Ikeda, Kazutaka; Taguchi, Ryo; Kobayashi, Tetsuyuki; Sato, Satoshi B.; Kobayashi, Toshihide; Stolz, Donna B.; Umeda, Masato

doi:10.1074/jbc.m111.327064

Cited by 43 publications

(42 citation statements)

References 34 publications

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“…After mechanical cell lysis, the SCMs can be separated by centrifugation, due to their high density. However, purities and yields of the membranes can vary in different laboratories because of the different experimental conditions used, including variations in buffer systems (26)(27)(28)(29)(30)(31)(32)(33)(34). In addition, a relatively large number of cells were needed in previous plasma membrane lipidomics studies using this method ( 30,31 ).…”

Section: Resultsmentioning

confidence: 99%

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Analysis of lipid-composition changes in plasma membrane microdomains

Ogiso

Taniguchi

Okazaki

2015

Journal of Lipid Research

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This article is available online at http://www.jlr.org and cholesterol (Chol) ( 1-5 ). These sphingolipid-rich microdomains are considered to be important sites for signal transduction and death receptor functions ( 6, 7 ). Depending on the local microenvironment, certain membrane proteins are preferentially localized inside (or outside) of the microdomains and serve as signaling platforms (8)(9)(10)(11)(12)(13)(14)(15)(16)(17). Recent data has indicated that membrane microdomains are dynamic nanometer-sized domains ( 18,19 ). Results from image analysis and single-molecule tracking studies have shown that these metastable membrane assemblies can be stabilized locally by lipid-lipid and lipidprotein interactions to coalesce and form functional domains and facilitate cell surface receptor signal transduction. A commonly held view is that microdomains regulate membrane protein functions by recruiting signaling molecules to the spatially limited region ( 7,20,21 ).Tight interactions between Chol and SM result in the formation of domains that are resistant to solubilization with detergents ( 22 ). This property is often used to prepare membrane microdomains. The typical preparation method involves the treatment of postnuclear lysates, generated by the removal of nuclei from cell lysates, with a nonionic detergent at low temperature, followed by separation of the low-density lipid fraction in a sucrose gradient ( 1 ). However, this fraction may contain a broad range of detergent-resistant membranes other than plasma membrane microdomains. Therefore, concerns have been raised that results obtained using this conventional method are not limited to events occurring on plasma membrane Membrane microdomains, including caveolae or lipid rafts, are plasma membrane domains that contain enhanced levels of sphingolipids, saturated fatty-acyl glycerophospholipids,

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Section: Resultsmentioning

confidence: 99%

“…The cationic colloidal silica beads method was used for preparing plasma membranes (26)(27)(28)(29)(30)(31)(32)(33)(34). Briefl y, this step was performed on ice using ice-cold buffers.…”

Section: Preparation Of Plasma Membranes With Cationic Colloidal Silimentioning

confidence: 99%

Analysis of lipid-composition changes in plasma membrane microdomains

Ogiso

Taniguchi

Okazaki

2015

Journal of Lipid Research

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“…Even cells that lack tight junctions due to combined removal of ZO-1 and ZO-2 still polarize and maintain at least some polarized lipid distribution 105,106 . It remains thus to be established to what extent the fence function is physiologically required for functional epithelia.…”

Section: Intramembrane Diffusion Barrier: the Fence Functionmentioning

confidence: 99%

Tight junctions: from simple barriers to multifunctional molecular gates

Zihni

Mills

Matter

et al. 2016

Nat Rev Mol Cell Biol

1,145

925

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Main body of text: 5983 words 2Epithelia and endothelia separate different tissue compartments and protect multicellular organisms form the outside world. This requires the formation of tight junctions, selective gates that control paracellular diffusion of ions and solutes. Tight junctions also form the border between the apical and basolateral plasma membrane domains and are linked to the machinery that controls apicobasal polarization. Additionally, signalling networks that guide diverse cell behaviours and functions are connected to tight junctions, transmitting information to and from the cytoskeleton, nucleus and different cell adhesion complexes. Here, we discuss recent advances in our understanding of the molecular architecture and cellular functions of tight junctions.Microscopists in the 19 th century described the paracellular space between neighbouring cells within an epithelial sheet to be sealed by a "terminal bar", a structure later resolved by electron microscopy into a composite of distinct cell-cell junctions that is now called the epithelial junctional complex and is formed by tight junctions, adherens junctions and desmosomes 1,2 . As the former two junctions are more tightly associated and often reside at the apical end of the lateral membrane, they are often referred to as the apical junctional complex (however, in endothelia, tight junctions and adherens junctions can be intercalated) (Fig. 1). Tight junctions are essential for barrier formation, and their primary physiological role is to function as paracellular gates that restrict diffusion on the basis of size and charge. Selective paracellular diffusion is an essential process for the maintenance of homoeostasis in organs and tissues. Tight junctions have long been the most enigmatic of all adhesion complexes and eluded a detailed molecular and functional analysis due to their complex architecture. Recent years have witnessed the identification of a large array of components associated with tight junctions implicating these junctions in an unexpected range of different functions, thereby challenging the traditional model, in which tight junctions are considered a simple diffusion barrier formed by a rigid molecular complex. In line with these various functions, mutations in genes encoding tight junction proteins have been linked to a range of inherited human diseases. Additionally, tight junction components are known to be targeted by a number of pathogenic bacteria and viruses, which hijack tight junction proteins to enter and infect cells, or target junctional signalling mechanisms to cross tissue barriers. Although tight junctions are a vertebrate junction, many of their components and functions are evolutionarily conserved (Box 1).The main purpose of this review is to examine the recent advances in the unravelling of the molecular architecture of tight junctions and understanding their functions. We will discuss recent exciting insights into how tight junctions function as signalling platforms that guide cell behaviour and differen...

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“…Hoechst 33342 (Life Technologies) was used at a dilution of 1:5000. Monomeric red fluorescent protein-lysenin (amino acids 161-298) was expressed in Escherichia coli and purified by affinity chromatography using TALON metal affinity resin (Clontech, Palo Alto, CA) as described previously (Ikenouchi et al, 2012). The culture supernatants of hybridoma cells producing anti-Forssman glycosphingolipid (clone 12B12) were used for immunofluorescence as described previously (Zinkl et al, 1996).…”

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confidence: 99%

EPLIN is a crucial regulator for extrusion of RasV12-transformed cells

Ohoka

Kajita

Ikenouchi

et al. 2015

Journal of Cell Science

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At the initial stage of carcinogenesis, a mutation occurs in a single cell within a normal epithelial layer. We have previously shown that RasV12-transformed cells are apically extruded from the epithelium when surrounded by normal cells. However, the molecular mechanisms underlying this phenomenon remain elusive. Here, we demonstrate that Cav-1-containing microdomains and EPLIN (also known as LIMA1) are accumulated in RasV12-transformed cells that are surrounded by normal cells. We also show that knockdown of Cav-1 or EPLIN suppresses apical extrusion of RasV12-transformed cells, suggesting their positive role in the elimination of transformed cells from epithelia. EPLIN functions upstream of Cav-1 and affects its enrichment in RasV12-transformed cells that are surrounded by normal cells. Furthermore, EPLIN regulates non-cell-autonomous activation of myosin-II and protein kinase A (PKA) in RasV12-transformed cells. In addition, EPLIN substantially affects the accumulation of filamin A, a vital player in epithelial defense against cancer (EDAC), in the neighboring normal cells, and vice versa. These results indicate that EPLIN is a crucial regulator of the interaction between normal and transformed epithelial cells.

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Lipid Polarity Is Maintained in Absence of Tight Junctions

Cited by 43 publications

References 34 publications

Analysis of lipid-composition changes in plasma membrane microdomains

Analysis of lipid-composition changes in plasma membrane microdomains

Tight junctions: from simple barriers to multifunctional molecular gates

EPLIN is a crucial regulator for extrusion of RasV12-transformed cells

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