Extracellular Matrix & Cell Adhesion Flashcards
What are some important functions of the ECM?
scaffold for cells regulates: - differentiation - migration - survival - proliferation - shape
What types of cells synthesize ECM macromolecules?
fibroblasts
chondroblasts (cartilage)
osteoblasts (bone)
What are the major components of the ECM?
glycosaminoglycans (GAGs)
Collagen
signaling molecules (fibronectin/ laminin)
Where is collagen I most often found?
connective tissues
Where is collagen IV most often found?
basal lamina
What do glucosaminoglycans GAGs consist of?
sugars and proteins (attached by o proteins 100.000s of repeats mil kda in size - extracellular mesh - charge -> hydration - modfied by sulfonation
How is hyluronic acid unique?
not attached to a protein
What are the 2 main functions of GAGs?
- maintain ECM integrity
- maintain gradients -> ensure correct localization of other cells
***(-) => help to maintain hydration of ECM
High pd on and off in leukocyte rolling -> slow down to enter
What is the function of collagen in the ECM?
regulate stiffness
What do multisignaling scaffolding domains bind?
collagen
GAGs
cells
ex) fibronectin, laminin
What is the general structure/ function of matrix metalloproteinases?
MMPs chop up proteins
- catalytic region binds Zn
- prodomain keeps them inactive
- cleave proteoglycans -> change directionality
- degrade cell cell adhesions
What are integrins?
Cell matrix adhesion molecules
What are the two types of fibrillar proteins?
collagen
elastin
what are 2 types of multidomain adapter proteins?
laminin - organizes basal membrane
fibronectin - organizes ECM into insoluble fibers
How is integrin cell signaling related to cell survival?
integrin bound to ECM-> survival pathway
0 ECM binding -> apoptosis
