Chapter 20: Integrating cells into tissues

Chapter 20: Integrating cells into tissues

1. 20.1: cell-cell and cell-extracellular matrix adhesion: an overview

   • cell-cell and cell-extracellular matrix (ECM) interactions are critical
     • assembling cells into tissues
     • controlling cell shape and function
     • determining the developmental fate of cells and tissues
   • cell-adhesion molecules (CAMs) mediate direct cell-cell adhesions
     • and directs adhesion receptors mediate cell-matrix adhesion
     • 4 families of CAMs
       • IgSF
       • integrins
       • selectins
       • cadherins
   • extracellular matrix
     • dynamic and complex meshwork of proteins and polysaccharides
       • contributes to the structure and function of a tissue

2. 20.2: cell-cell and cell-extracellular matrix junctions and their adhesion molecules

   • anchoring junctions
     • focal contacts
     • desmosomes
     • hemidesmosomes
   • cadherins and interns mediate cell-cell and cell-ecms junctions
   • tight junctions define epithelial cell polarity and regulate extracellular flow of water and solutes from one side of the epithelium to the other
   • gap junctions connect the cytoplasm of adjacent cells for metabolic and electrical coupling
   • key junctional proteins
     • cadherins
     • dapper proteins that associate with cadherins
     • integrins
     • tight junction proteins
     • connexins

3. 20.3: the extracellular matrix I: the basal lamina

   • basal lamina ECM connects most epithelia and other organized groups of cells to adjacent connective tissues
   • 4 multi domain ECM proteins
     • laminin
     • collagen IV
     • perlecan
     • nidogen
   • ECM proteins bind to each other and to cellular receptors

4. 20.4: the extracellular matrix II: the connective tissue

   • integrin-containing clusters of proteins
     • focal adhesion
     • focal contact-like adhesive structures
   • dystroglycan links the actin cytoskeleton to the surrounding matrix
     • defects cause different types of muscular dystrophy
   • movement and adhesive properties of leukocytes in the bloodstream

5. 20.5: adhesive interactive in motile and nonmotile cells