Week 7 Flashcards
describe the cells/tissues that take part in firm adhesion
- muscle cells/connective tissue of tendons
- skin epithelial cells
transient adhesion examples
- leukocytes binding to epithelial cells
- cell attachment to ECM during migration
describe the role of anchoring junctions and provide examples of Cell-cell/cell-matrix adhesions
- facilitate attachment to cytoskeleton and transmit physical forces
CELL-CELL
- adherens, desmosomes
CELL-MATRIX
- actin-linked/hemidesmosomes
describe role of occluding junctions and provide an example.
- in epithelial cells?
- state of permeability?
- seals gap between cells (ex. tight junctions between epithelial cells)
– leads to impermeability/selective permeability
role of channel forming junctions and provide example
GAP junctions
– allow passage of small molecules, ions between cytoplasm of cells
Role of signal relaying junctions, provide example
- allows signal transduction between cells
- cell-cell contact sites (neuronal synapses)
cell-cell adhesion molecules and their properties
CADHERIN– binds actin (adherens junction) or IF (desmosomes)
Ig Family– signal relaying
Selectins– binds actin cytoskeleton, non-junctional
cell-matrix adhesion molecules and their properties
INTEGRINS
- usually linked to actin cytoskeleton– focal adhesion
- when linked to IF– form hemidesmosomes
describe cadherin and its importance in body
- adhesion proteins whose homotypic association is Ca dependent
- important in cell segregation during embryonic development
importance of catenin in cytoplasmic domain of cadherins
- catenin facilitates linking of cytoplasmic cadherin domain to actin cytoskeleton
describe the role of LFA1 (alphaL-Beta2) integrin upon antigen recognition
- LFA1 activation by T-cell receptor leads to stronger binding to ICAM
