Cell Adhesions

Question 1

Focal Adhesions

Answer 1

Subcellular structures through which mechanical force and regulatory signals are transmitted between the ECM and the cell interior.

Question 2

Hemidesmosome

Answer 2

• Function to anchor epithelial cells to the underlying basal lamina
• Adhesion protein: Integrins
• Ligand: ECM proteins
• Cytoskeletal attachment: Intermediate filaments.

Question 3

Adherens Junctions

Answer 3

• Bind cells together (cytoskeletons)
• Cadherin adhesion receptors (calcium dependent) are important in the formation of these junctions
• Adhesion protein: Cadherin
• Ligand: cadherin in neighbor cell
• Intracellular attachment: actin filaments

Question 4

First principle of Adhesion

Answer 4

Cells define their capacity for adhesive interactions by selectively expressing plasma membrane receptors (CAMs) with limited ligand -binding activity

Question 5

Second principle of Adhesion

Answer 5

Many adhesion proteins bind one main ligand, and many ligands bind a single type of receptor

Question 6

Third principle of Adhesion

Answer 6

Cells modulate adhesion by controlling the surface density, state of aggregation, and state of activation of their adhesion receptors

Question 7

Fourth principle of Adhesion

Answer 7

The rates of ligand binding and dissociation are important determinants of cellular adhesion

Question 8

Fifth principle of Adhesion

Answer 8

Many adhesion receptors interact with the cytoskeleton inside the cell

Question 9

Sixth principle of adhesion

Answer 9

Association of ligands with adhesion receptors can activate intracellular transduction pathways, leading to changes in gene expression, cellular differentiation, secretion, motility, receptor activation, and cell division

Question 10

What are the two types of integrin dependent junctions?

Answer 10

Focal adhesions and hemidesmosomes

Question 11

Basal lamina

Answer 11

Separates epithelium from underlying CT

Question 12

Von Willebrand disease

Answer 12

Deficiency in GPIb which allows Von Willebrand factors to bind to platelets

Question 13

Glanzmann thrombasthenia

Answer 13

Deficiency in GPIIb which allows binding of fibrinogen

Question 14

Leukocyte Deficiency Disease

Answer 14

Mutations in genes involved in trans-endothelial cell migration > impaired migration of the leukocytes into infected tissue > impaired ability to fight infection

Question 15

Disintegrins

Answer 15

Promote cell de-adhesion by competitively inhibiting integrins

Question 16

Integrins

Answer 16

Found in hemidesmosomes and focal adhesions

Question 17

Mechanical tension activates…

Answer 17

signaling pathways at adhesion sites