ECM And Collagen

Question 1

What are the functions of the ECM?

Answer 1

Reservoir for growth factors
Provides survival and differentiation signals to cells
Transmits force
Withstand compression forces
Mechanical basis for cell attachment and movement
Provides a scaffold for tissue development

Question 2

What motif allows collagen to form a triple helix?

Answer 2

Gly-X-Y

Question 3

Why is glycine particularly important in the structure of collagen?

Answer 3

It is the only amino acid small enough and neutral to fit into the centre of (and thus allow) the triple helix structure of collagen

Question 4

Describe collagen synthesis.

Answer 4

Collagen is first synthesised as a pro alpha chain and hydroxylated prolines and lysines are added. Lysine residues are used as a template for adding sugar molecules and proline residues are important for the helix structure. Glycosylation occurs, then self assembly into three pro alpha chains
Procollagen is secreted from the cell and self assembly into fibrils occurs, fibrils then aggregate to form fibres
Collagen folding into its final shape and collagen modification occur simultaneously

Question 5

What part of the structure of collagen is most often affected by mutations?

Answer 5

Glucone