Elastin and Fibrillin
Start with the big picture
Elastin is secreted as tropoelastin by fibroblasts and vascular smooth muscle cells, then deposited on fibrillin-rich microfibrils. Its amino-acid composition supports flexible coils, while lysyl oxidase–mediated cross-links help create elastic fibers. Elastin’s low turnover, enzymatic degradation, and protective role of α1-antitrypsin are relevant to aging and disease. Fibrillin forms calcium-binding microfibrils that scaffold elastin and sequester TGF-β. Defects in elastin or fibrillin are associated with distinct clinical conditions, including Williams syndrome, Marfan syndrome, and congenital contractural arachnodactyly. Together, these proteins illustrate how extracellular-matrix structure, synthesis, maintenance, and genetic changes can affect tissue function.
What you'll learn
- Describe elastin’s distribution and role in tissue stretch and recoil.
- Explain tropoelastin deposition and the role of lysyl oxidase cross-linking.
- Summarize fibrillin’s scaffold, calcium-binding, and TGF-β-sequestering functions.
- Distinguish the connective-tissue disorders associated with ELN, FBN1, and FBN2 changes.
- Identify key mechanisms of elastin degradation and fibrillin-related ocular involvement.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
