The tight junction (TJ) and its adhesion molecules, claudins, are responsible for the barrier function of simple epithelia, but TJs have not been thought to play an important role in mammalian stratified including epidermis. Here we generated claudin-1–deficient mice found that animals died within 1 d birth with wrinkled skin. Dehydration assay transepidermal water loss measurements revealed these epidermal was severely affected, although layered organization keratinocytes appeared be...

For epithelia to function as barriers, the intercellular space must be sealed. Sealing two adjacent cells at bicellular tight junctions (bTJs) is well described with discovery of claudins. Yet, there are still barrier weak points tricellular contacts, where three join together. In this study, we identify tricellulin, first integral membrane protein that concentrated vertically oriented TJ strands contacts. When tricellulin expression was suppressed RNA interference, epithelial compromised,...

There are two strains of MDCK cells, I and II. cells show much higher transepithelial electric resistance (TER) than II although they bear similar numbers tight junction (TJ) strands. We examined the expression pattern claudins, major components TJ strands, in these cells: claudin-1 -4 were expressed both whereas claudin-2 was restricted to cells. The dog cDNA then introduced into mimic claudin Interestingly, TER values clones stably expressing (dCL2-MDCK I) fell levels (>20-fold...

Claudin-2 is highly expressed in tight junctions of mouse renal proximal tubules, which possess a leaky epithelium whose unique permeability properties underlie their high rate NaCl reabsorption. To investigate the role claudin-2 paracellular transport this nephron segment, we generated knockout mice lacking ( Cldn2 −/− ) . The displayed normal appearance, activity, growth, and behavior. Light microscopy revealed no gross histological abnormalities kidney. Ultrathin section freeze-fracture...

Tight junctions (TJs) establish the epithelial barrier and are thought to form a membrane fence regulate polarity, although roles of TJs in polarity remain controversial. Claudins constitute TJ strands conjunction with cytoplasmic scaffolds ZO-1 ZO-2 play pivotal formation. However, how claudins other proteins cooperate organize remains unclear. Here, we systematically knocked out components by genome editing show that while ZO-1/ZO-2-deficient cells lacked structures barriers,...

In well polarized epithelial cells, closely related ZO-1 and ZO-2 are thought to function as scaffold proteins at tight junctions (TJs). cells the initial phase of polarization, these recruited cadherin-based spotlike adherens (AJs). As a first step clarify ZO-1, we successfully generated mouse cell clones lacking expression (ZO-1-/- cells) by homologous recombination. Unexpectedly, in confluent cultures, ZO-1-/- were highly with organized AJs/TJs, which indistinguishable from those ZO-1+/+...

The tight junction (TJ) strand is a linear proteinaceous polymer spanning plasma membranes, and each TJ associates laterally with another in the apposing membranes of adjacent cells to form “paired” strands. Claudins have been identified as major constituents strands, when exogenously expressed L fibroblasts, they polymerize into paired which are morphologically similar strands epithelia. Here, we show that fusion protein GFP claudin-1 can also allowing us directly observe individual claudin...

Claudins are cell adhesion molecules working at tight junctions (TJs) that directly involved in compartmentalization multicellular organisms. The cochlea includes a rather peculiar compartment filled with endolymph. This is characterized by high K+ concentration (∼150 mM) and positive endocochlear potential (∼90 mV; EP), both indispensable conditions for cochlear hair cells to transduce acoustic stimuli electrical signals. These thought be generated the stria vascularis, which adjacent...

Tricellular tight junctions (tTJs) are specialized (TJs) that seal the intercellular space at tricellular contacts (TCs), where vertices of three epithelial cells meet. Tricellulin and angulin family membrane proteins known constituents tTJs, but molecular mechanism tTJ formation remains elusive. Here, we investigated roles angulin-1 tricellulin in MDCK II by genome editing. Angulin-1–deficient lost plasma contact TCs with impaired barrier function. The C terminus bound to TJ scaffold...

ZO-1, ZO-2, and ZO-3 are closely related MAGUK family proteins that localize at the cytoplasmic surface of tight junctions (TJs). ZO-1 ZO-2 expressed in both epithelia endothelia, whereas is exclusively epithelia. In spite intensive studies these TJ MAGUKs, our knowledge their functions vivo, especially those ZO-3, still fragmentary. Here, we have generated mice, as well F9 teratocarcinoma cell lines, do not express by homologous recombination. Unexpectedly, ZO-3(-/-) mice were viable...

ABSTRACT Septate junctions (SJs) are membrane specializations that restrict the free diffusion of solutes through paracellular pathway in invertebrate epithelia. In arthropods, two morphologically different types septate observed; pleated (pSJs) and smooth (sSJs), which present ectodermally endodermally derived epithelia, respectively. Recent identification sSJ-specific proteins, Mesh Ssk, Drosophila indicates molecular compositions sSJs pSJs differ. A deficiency screen based on...

The apical junctional complex is composed of various cell adhesion molecules and cytoplasmic plaque proteins. Using a monoclonal antibody that recognizes chicken 155-kDa antigen (p155) localizing at the complex, we have cloned cDNA its mouse homologue. full-length p155 encoded 148-kDa polypeptide containing coiled-coil domain with sequence similarity to cingulin, tight junction (TJ)-associated protein. We designated this protein JACOP (junction-associated protein). Immunofluorescence...

The claudin family of membrane proteins is responsible for the backbone structure and function tight junctions (TJs), which regulate paracellular permeability epithelia. It thought that each subtype has its own unique combination expressed subtypes determines property epithelium. However, many issues remain unsolved in regard to functions, including detailed functional differences between effect combinations specific on TJs. To address these issues, it would be useful have a way...

Abstract: Claudins and occludin are integral membrane proteins at tight junctions (TJs). We examined subcellular localization of claudin‐5 in dermal vascular endothelia. Immunofluorescence staining showed that was expressed the cell–cell border endothelia mouse skin. However, some vessels, expression markedly decreased or absent amount by double‐immunofluorescence stainings with PECAM‐1 PAL‐E. In contrast, not detected vessels. Freeze‐fracture immunoreplica electron microscopy on...

ABSTRACT Smooth septate junctions (sSJs) contribute to the epithelial barrier, which restricts leakage of solutes through paracellular route in cells Drosophila midgut. We previously identified three sSJ-associated membrane proteins, Ssk, Mesh and Tsp2A, showed that these proteins were required for sSJ formation intestinal barrier function larval Here, we investigated roles sSJs adult Depletion any from enterocytes resulted remarkably shortened lifespan dysfunction flies. Interestingly,...

Abstract Claudin‐based tight junctions (TJs) are formed at the most apical part of cell–cell contacts in epithelial cells. Previous studies suggest that scaffolding proteins ZO‐1 and ZO‐2 (ZO proteins) determine location TJs by interacting with claudins, but this idea is not conclusive. To address role ZO binding to claudins TJs, a COOH‐terminal PDZ domain motif‐deleted claudin‐3 mutant, which lacks protein binding, was stably expressed claudin‐deficient MDCK The COOH‐terminus‐deleted...

Hagfish (Eptatretus burgeri) are agnathous and the earliest vertebrates still in existence. Pavement cells adjacent to mitochondria-rich show orthogonal arrays of particles (OAPs) gill hagfish, a known ultrastructural morphology aquaporin (AQP) mammalian freeze-replica studies, suggesting that an AQP homolog exists pavement cells. We therefore cloned water channels from hagfish examined their molecular characteristics. The [E. burgeri AQP4 (EbAQP4)] encodes 288 amino acids, including two NPA...

The anterior pituitary gland regulates growth, metabolism, and reproduction by secreting hormones. Folliculo-stellate (FS) cells are non-endocrine located among hormone-producing in the glands. They form follicular lumens, which sealed tight junctions (TJs). Although FS hypothesized to contribute fine-tuning of endocrine cells, little is known about exact roles cells. Here, we investigated molecular composition TJs We demonstrated that occludin a good marker for examined structure lumens...

Smooth septate junctions (sSJs) regulate the paracellular transport in intestinal tract arthropods. In Drosophila, organization and physiological function of sSJs are regulated by at least three sSJ-specific membrane proteins: Ssk, Mesh Tsp2A. Here, we report a novel sSJ protein, Hoka, which has single membrane-spanning segment with short extracellular region, cytoplasmic region Tyr-Thr-Pro-Ala motifs. The larval midgut hoka mutants shows defect structure. Hoka forms complex Tsp2A, is...

Abstract Smooth septate junctions (sSJs) contribute to the epithelial barrier, which restricts leakage of solutes through paracellular route cells in Drosophila midgut. We previously identified three sSJ-associated membrane proteins, Ssk, Mesh, and Tsp2A, showed that these proteins were required for sSJ formation intestinal barrier function larval Here, we investigated roles sSJs adult Depletion any sSJ-proteins from enterocytes resulted remarkably shortened lifespan dysfunction flies....

Septate junctions (SJs) are membrane specializations that restrict the free diffusion of solutes through paracellular pathway in invertebrate epithelia.In arthropods, two morphologically different types septate observed; pleated (pSJs) and smooth (sSJs), which present ectodermally endodermally derived epithelia, respectively.Recent identification sSJ-specific proteins, Mesh Ssk, Drosophila indicates molecular compositions sSJs pSJs differ.A deficiency screen based on immunolocalization...

Abstract Tricellular tight junctions (tTJs) are specialized (TJs) that seal the intercellular space at tricellular contacts (TCs), where vertices of three epithelial cells meet. Tricellulin and angulin family membrane proteins known constituents tTJs, but molecular mechanism tTJ formation remains elusive. Here, we investigated roles angulin-1 tricellulin in MDCK II by genome editing. Angulin-1-deficient lost plasma contact TCs with impaired barrier function. The COOH-terminus bound to TJ...