CELL-TO-CELL JUNCTIONS Michaela Tiffany. SURFACE MARKERS Structure: Variable, integral proteins or glycolipids in plasma membrane Function: Identify the.

CELL-TO-CELL JUNCTIONSMichaela 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