Cell Junctions, Cell Adhesion, and the Extracellular Matrix
The role of tight junction
Anchoring junction
Adherens junction
Desmosomes
Focal adhesions
Desmosomes and Hemidesmosomes
Gap junction channel
Gap junctions
Gap junction coupling in the ovarian follicle
The regulation of gap-junction coupling by a neurotransmitter
Cell-Cell Adhesion Three mechanisms of cell-cell adhesion
The structure and function of cadherins
Cadherin-dependent cell sorting
Cadherin diversity in the CNS
The linkage of classical cadherins to actin filaments
The structure and function of selectins
The cell adhesion protein N-CAM
The connective tissue underlying an epithelium
The repeating disaccharide sequence of a dermatan sulfate glycosaminoglycan (GAG) chain
The relative dimensions and volumes occupied by various macromolicules
The repeating disaccharide sequence in hyaluronan
The linkage between a GAG chain and its core protein in proteoglycan molecule
Examples of proteoglycan
An aggrecan
Structure of a typical collagen molecule
Type IX collagen
Stretching a network of elastin molecules
The structure of fibronectin dimer
The structure of laminin
Three ways in which basal laminae are organized
The molecular structure of a basal lamina
The comparative shapes and sizes of some of the major ECM macromolecules
The ECM can influence cell shape, cell survival, and cell proliferation
Anchorage dependence and the importance of cell spreading
The degradation of matrix components Slow and continuous turnover of ECM Matrix metalloproteases Serine protease Controlled, specific degradation -> important to cell migration *Clear a path through matrix *Expose cryptic sites that promote cell binding, cell migration *Promote cell detachment *Release signal proteins that stimulate cell migration Tightly controlled Local activation; plasminogen activator activates inactive plasminogen to plasmin Confinement by cell-surface receptor; urokinase-type plasminogen activator Secretion of inhibitor; tissue inhibitors of metalloproteases, serpins
The importance of proteases bound to cell-surface receptors
The structure of an integrin receptor
The regulation of the extracellular binding activity of a cell’s integrins from within
Excessive numbers of focal adhesions in FAK-deficient fibroblasts
Matrix-dependent cell survival in the formation of the proamniotic cavity