Lecture - Focal adhesions (1)

What is the function of the extracellular matrix (ECM)?

The ECM provides essential physical scaffolding for cells and biomechanical cues.

What are integrins?

Integrins are transmembrane heterodimers that link the extracellular matrix to the actin cytoskeleton.

Describe the two conformations of integrins.

Integrins switch between active (binding sites exposed) and inactive (binding sites hidden) conformations.

What are focal adhesions?

Focal adhesions are short-lived and dynamic connections between migrating cells and the ECM, playing a role in muscle attachment.

What is talin's role in cell-matrix adhesions?

Talin is a dimer that binds integrin and actin, stabilizing them at focal adhesions.

How do integrins cluster?

Integrins cluster to form strong adhesions that connect the ECM to intracellular components.

What is the role of vinculin in integrin-mediated adhesion?

Vinculin stabilizes talin and integrin at focal adhesions, aiding in integrin clustering for adhesion growth.

What does the binding of integrins to extracellular matrix proteins facilitate?

It facilitates signal transduction between the extracellular environment and the cell's interior.

How does talin buffer forces?

Talin buffers forces through the folding and unfolding of its various rod domains.

What is the significance of mechanosignaling in cell-matrix adhesions?

Mechanosignaling involves the response of adhesion proteins to mechanical stress, crucial for maintaining cell integrity and function.

What happens to muscles without integrins or components of the myotendinous junctions?

Without integrins or other components of the myotendinous junctions, muscles round up due to the loss of structural stability.

What are focal adhesions (FAs)?

Focal adhesions are connections between integrins and the extracellular matrix, linking the ECM to the cytoplasm and facilitating signal transduction.

What is FAK in relation to focal adhesions?

FAK (Focal Adhesion Kinase) is a kinase that plays a crucial role in cell-matrix adhesions and signaling pathways in focal adhesions.

How do talin and vinculin interact in focal adhesions?

Talin, a dimer, binds to integrin and actin, while vinculin stabilizes the complex of talin and integrin at focal adhesions.

What is the role of mechanosignaling in cell-matrix adhesions?

Mechanosignaling involves the response of adhesion proteins to mechanical stress, essential for maintaining cell integrity and function.

Describe the conformations of adhesion proteins.

Adhesion proteins such as integrins can exist in open/active (binding sites exposed) and closed/inactive (binding sites hidden) conformations.

How does talin buffer forces in focal adhesions?

Talin buffers forces through the folding and unfolding of its various rod domains, enabling the complex to withstand mechanical stress.