Download Cell-to-cell junctions

CELL-TO-CELL
JUNCTIONS
Michaela Tiffany
SURFACE MARKERS
• Structure: Variable, integral proteins or glycolipids in plasma membrane
• Function: Identify the cell
• Example: MHC complexes, blood groups, antibodies
SEPTATE JUNCTIONS/TIGHT
JUNCTIONS
• Structure: Tightly bound, leakproof, fibrous claudin protein seal that surrounds
the cell
• Function: Holds cells together such that materials pass through not between
the cells
• Example: Junctions between epithelial cells in the gut
ADHESIVE JUNCTION
(DESMOSOME)
• Structure: Variant cadherins, desmocollins, blind to intermediate filaments of
cytoskeleton
• Function: Creates strong flexible connections between cells
• Found in vertebrates
• Example: Epithelium
ADHESIVE JUNCTION(ADHERENS
JUNCTIONS)
• Structure: Classical cadherins, bind to microfilaments of cytoskeleton
• Function: Connects cells together
• Oldest form of cell junction
• Found in all multicellular organisms
• Example: Tissues with high mechanical stress, such as the skin
ADHESIVE JUNCTION
(HEMIDESMOSOME, FOCAL
ADHESION)
• Structure: Integrin proteins bind cell to extracellular matrix
• Function: Provide attachment to a substrate
• Example: Involved in cell movement and important during development
COMMUNICATING JUNCTION
(GAP JUNCTION)
• Structure: Six transmembrane connexons/pannexin proteins creating a pore
that connects cells
• Function: Allows passage of small molecules from cell to cell in a tissue
• Example: Excitable tissue such as heart muscle
COMMUNICATING JUNCTION
(PLASMODESMATA)
• Structure: Cytoplasmic connections between gaps in adjoining plant cell
walls
• Function: Communicating junctions between plant cells
• Example: Plant tissues
• All information in this power point can be found in Mgraw Hill Biology 10th
Edition on pages 82-85