Extracellular Matrix Flashcards
Major function of fibroblast
Make and remodel collagen fibres
Mammalian tissue
25% if total protein mass
Helix
3 alpha chains
Glycine
- every third residue in alpha-chain
- smallest amino acid firts center if triple helix
- allows tight packing of alpha chain
How cross-links are formed
- secreted lysyl oxidase deaminages lysine and hydroxylysine residues
- highly reactive aldehyde groups form spinganeous covalent bonds with each other or other lysine and hydroxylysine residues
- non-helical segments at end of collagen molecules form most cross-links
Glycosaminoglycan chains (GAGs)
- negatively charged
- interact with collagen
- highly compressive
- interact with growth factors
Versatile function of ECM in cancer
ECM protein domains and the architecture of ECM proteins contain information of biological and evolutionary value
Normal stem cell niche
ECM components are necessary for the acquisition and maintenance of stem cell properties
Cancer stem cell niche
An “abnormal niche ECM” or loss of ECM contact can lead to loss of stem cell polarity and a failure to maintain stem cell properties
Collagens
Major proteins in ECM
Function of cross-links
- increased tensile strength
- levels and types of collagen cross-linking varies from tissue to tissue
- increased collagen cross-linking is linked to the promotion of cancer
Anchorage to the basement membrane is essential for…
- cell polarity
- cell differentiation
- organisatjon of plasma membrane protein complexes
What can determine cell behaviour?
ECM elasticity
SFK
Src family kinase
FAK 1
Focal adhesion kinase
