Extracellular Matrix Flashcards
What are some types of extracellular matrix
bone, hair, tendon, skin
What is the extracellular matrix
extracellular meshwork of proteins and hydrated macromolecules
What does the ECM maintain
Migration, tissue integrity, proliferation, differentiation
What are the extracellular matrix types?
Fibrous proteins, adhesion proteins, hydrated macromolecules
Name some fibrous proteins
collagens, elastins
Name some adhesion proteins
fibronectin, laminin
Name some hydrated macromolecules
glycosaminoglycans, proteoglycans
Describe the structure of collagen
triple helix of alpha chains
What produces collagen
fibroblasts, epithelial cells
What disease is caused by collagen defects
Ehlers-danlos sydrome
What is hydroxylated in collagen synthesis
prolines, lysines
What is glycosylated in collagen synthesis
hydroxylysines
What catalyses elastin synthesis
lysyl oxidase
What elastin laid down over
microfibril scaffold of fibrillin
WHat is the precursor for elastin
tropoelastin
What are GAGs
sugar - glycosaminoglycans
What are sugars
ground substance
What is the difference between proteoglycans and glycoproteins
proteoglycans - higher sugar %
What are proteoglycan complexes made of
proteins and polysaccharides
What do proteoglycan complexes form complexes with?
collagen and hyaluronan
What are proteoglycan complexes
aggregan aggregate
What is aggregan aggregate
protein
What encodes aggregan aggregate
ACAN gene
Describe hyaluronic acid
non sulphated, large MW
How is hyaluronic acid secreted
across the plasma membrane
Where is hyaluronic acid found?
skin, connective tissue, eyes
What does hyaluronic acid retain
water
What does hyaluronic acid form
protein complexes
Describe the extracellular matrix functions
structural, elastic, space filling, adhesive
What is laminin
adhesive glycoprotein
What is laminin comprised of ?
integrin, nidogen, globular domains
What chains are laminin comprised of?
alpha, beta, gamma
What is fibronectin
adhesive glycoproteins
What are integrins?
ECM receptors, mechanical signalling linkers
What do integrins bind to?
divalent cations
What do integrins link
ECM, cytoskeleton
What are integrins involved in?
cell movement
What can integrin defects cause?
knockouts - embryonic lethal, platelet defects
What does defects in b1 integrin cause
knockout embryonic lethal - implantation
What do defects in a5 integrin cause
knockout embryonic lethal - mesoderm development
