Intercellular Adhesions

Cards (44)

  • What are PROMINENT in epithelia?
    Junctions
  • What provides a means for anchoring cells between adjacent epithelial cells and the basal laminae?
    Adhesions and junctions
  • What are the 4 types of Intercellular adhesions and other junctions?
    Tight junctions, Adherins, Gap junctions, hemidesmosomes
  • Tight junction is also known as what?
    Occluding junctions
  • Adherens is also known as what?
    Anchoring junctions
  • Tight or occluding junctions: form a seal between ADJACENT cells
  • Adherens of anchoring junctions: sites of strong cell adhesion
  • Gap junctions: channels for communication between adjacent cells
  • Hemidesmosomes: anchors cells to the basal lamina
  • Tight junctions are also known as what?
    Zonulae occludens
  • What type of junction are the MOST APICAL?
    Tight junctions
  • In tight junction, the seal between the two cell membranes is due to tight interactions between the transmembrane proteins what?
    claudins and occludin
  • Tight junctions: serve as fences restricting movements of membrane lipids and proteins at the apical cell surface into the lateral and basal surfaces, and vice versa.
  • Adherens junction is also known as what?
    Zonula adherens
  • What type of junction is immediately below the TIGHT JUNCTION?
    Adherens junction
  • Adherens junctions firmly anchors a cell to its neigbors mediated by what?
    Cadherins
  • At their cytoplasmic ends, cadherins bind to what that link to actin filaments with actin-binding proteins?
    Catenins
  • The actin filaments linked to the adherens junctions form part of the “TERMINAL WEB,” a cytoskeletal feature at the apical pole in many epithelial cells
  • Desmosomes is also known as what?
    Macula adherens
  • What type of junction resembles a single “spot-weld” and does not form a belt around the cell?
    Desmosomes
  • Desmosomes: disc-shaped structures at the surface of one cell that are matched with identical structures at an adjacent cell surface - provide firm cellular ad
  • Gap junctions: mediate intercellular communication rather than adhesion or occlusion between cells
  • What type of junction is functionally important in nearly all mammalian tissues as, it permit intercellular exchange of molecules with small ( <1.5 nm) diameters?
    Gap junctions
  • INTEGRINS of hemidesmosomes bind primarily to LAMININ molecules in the basal lamina
  • Which among the junction has NO cytoskeletal component?
    Gap junction
  • Gap junctions: allows DIRECT TRANSFER of small molecules and ions from one cell to another.
  • Desmosome: Autoimmunity against DESMOGLEIN I leads to dyshesive skin disorders characterized by reduced cohesion of epidermal cells
  • Gap junctions: Mutations in various CONNEXIN genes have been linked to certain types of DEAFNESS and peripheral neuropathy
  • HEMIDESMOSOME: Mutations in INTEGRIN-B4 gene are linked to some types of EPIDERMOLYSIS BULLOSA, a skin blistering disorder
  • DESMOSOME: Cadherin family proteins like desmogleins and desmocolin
  • TIGHT JUNCTION: Seals ADJACENT CELLS to one another, controlling passage of molecules between them, separates apical and basolateral membrane domains
  • What is the cytoskeletal component of tight junction?
    Actin filament
  • Adherent junction: LOSS of E-cadherin in epithelial cell tumors (carcinomas) promotes tumor invasion and the shift to malignancy
  • What type of cytoskeletal component do hemidesmosome have?
    Intermediate filaments
  • What type of cytoskeletal component do adherent junction have?
    actin filaments
  • Gap junction: connexin
  • HEMIDESMOSOME: Integrins
  • ADHERENT JUNCTION: Provides points linking the cytoskeletons of adjacent cells; strengthens and stabilizes nearby tight junctions
  • ADHERENT JUNCTION: E-cadherin and catenin complexes
  • HEMIDESMOSOME: Anchors cytoskeleton to the basal lamina