Types of collagen, synthesis, and diseases Flashcards
Granulation tissue
III
OI results from impairement of:
Alpha triple helix formation during collagen synthesis
Skin
Mainly I, some III
What cofactor is required for hydroxylation of proline and lysine during collagen synthesis?
Vitamin C
In what form is collagen exocytosed into ECM during synthesis?
Procollagen (already in triple helix)
Most common type of Ehlers-Danlos?
Hypermobile type (joint instability)
Where is the alpha chain triple helix of precollagen formed?
RER of fibroblast
Cornea
I
Consensus sequence of collage
Gly-X-Y
Best reflection of collagen synthesis?
Glycine uptake by fibroblasts
Where is type IV collagen found?
Basement membrane, basal lamina, lens
What causes Menke disease?
Lack of copper transport and absorption –> no copper for lysyl oxidase cross-linking of lysine-hydroxylysine
Fascia
I
Where is type I collagen found?
Bone, skin, tendon, fascia, dentin, cornea, late wound repair
Kinky hair + growth retardation + hypotonia
Menke disease
Lens
IV
Which preprocollagen residues are hydroxylated in the RER of fibroblasts?
Proline and lysine
Uterus
III
Where is type III collagen found?
Blood vessels, granulation tissue, fetal tissue, uterus, skin
Hyperextensible skin + easy bruising/tendency to bleed + hypermobile joints
Ehlers-Danos
Basement membrane
IV
Multiple fractures + hearing loss + dental imperfections
OI
Tendon
I
Where is type II collagen found?
Cartilage (including hyaline), nucleus pulposus, vitreous body