Cell Adhesion

Question 1

What molecules are involved with cell-cell adhesions?

Answer 1

Cadherins

Integrins

Question 2

What are the functions of cell-cell communication?

Answer 2

WOund healing
Inflammation
Immune response
Tumor metastasis
BLood clotting
Growth

Question 3

Is cell adherence reversible?

Answer 3

Yes

Specific and reversible

Question 4

What are the types of adhesion?

Answer 4

Homotypic adhesion (similar cells)
Heterotypic adhesion (Dissimilar cells)

Question 5

What is an example of a hetertypic adhesion

Answer 5

Neuron and schwann cell

Question 6

What are N-CAMs?

Answer 6

Neural Adhesion molecule

Question 7

Where are cadherins found?

Answer 7

Plasma membrane

Question 8

What moelcule do cadherins need to function?

Answer 8

Calcium allows interaction with neighboring cell via cadherins

Question 9

What type of side chains do cadherins have?

Answer 9

Carbohydrate side chains

Question 10

What type of junction do cadherins bind through?

Answer 10

Adherens junctions with Actin cytoskeleton & desmosomes

Question 11

What are Integrins

Answer 11

Linker proteins

Question 12

What is a benefit of integrins

Answer 12

Binding is weak with low affinity which allows cells to migrate

Question 13

What is the organization of cell adhesion?

Answer 13

1. Cytoskeletal element (Actin)
2. Adaptor proteins
3. Transmembrane adhesion proteins (Fibronectin)
4. Extracellular ligands (COllagen)

Question 14

What are the types of cell junctions?

Answer 14

Adhesive (Desmosome, hemidesmosome, adherens junctions)

Tight junctions

Gap junctions

Question 15

WHat is the purpose of adhesive junctions?

Answer 15

Connect cytoskeleton to cytoskeleton

Allows cells to function as a unit

Question 16

What types of cells are adhesive junctions most common in?

Answer 16

Cells that experience high stress and pressure (heart, bladder, stomach)

Question 17

What types of proteins to adhesive junction contain?

Answer 17

Intracellular attachment proteins

Transmembrane linker proteins

Question 18

What are intracellular attachment proteins?

Answer 18

Located inside plasma membrane

Forms thick plaque on cytoplasmic side

Question 19

What are transmembrane linker proteins?

Answer 19

Located outside plasma membane

Binds cells to ECM

Question 20

What tissues are desmosomes often found?

Answer 20

Heart, skin, neck of uterus where structural integrity is important

Question 21

What is the desmosome made of?

Answer 21

Junctional complex

Cadherins, integrating membranes, transmembrane linker proteins

Question 22

What is the function of the hemidesmosome?

Answer 22

Connects Epithelial cell to basal membrane using Integrins (laminins)

Question 23

What are adhesive junctions?

Answer 23

Adhesion Belt encompasses entire cell and connects cytoskeleton to adjacent cell via actin and integrins

Question 24

Where are adhesive junctions found?

Answer 24

Layers of tissue that line body cavities

Question 25

What is a gap junction?

Answer 25

A channel formed by six connexins for reciprocal exchange of ions and small molecules

Question 26

WHat is Zonula occludens protein-1

Answer 26

Major tight junction structural protein

Question 27

What is the most common junction?

Answer 27

Gap Junction

Question 28

Where are Gap junctions most commonly found?

Answer 28

In all cells Specifically cells requiring simultaneous reaction: Muscle Nerve

Question 29

Is there space between tight junctions?

Answer 29

No

Question 30

What are the tightest junctions of the body?

Answer 30

Epithelial cells of inner ear | Blood-brain barrier

Question 31

What are the major types of proteins in tight junctions?

Answer 31

Claudins, occuludins

Question 32

What do tight junctions bind?

Answer 32

Cytoskeleton to adjacent cells

Question 33

Describe the order to the junctional complex in a cell from basal layer up

Answer 33

Desmosome Adhesion belt Tight junction

Question 34

What is Pemphigus?

Answer 34

Auto-immune disease that attacks Cadherins Causes skin to fall off

Question 35

What is the treatment for Pemphigus?

Answer 35

Corticosteroid injections

Question 36

What desmogelin is the target of pephigus vulgaris? IgA pemphigus? Pemphigus foliaceus?

Answer 36

Dsg3 Dsc1 Dsg1

Question 37

What is the most common type of Pephigus?

Answer 37

Pemphigus foliaceus

Question 38

What is the importance of alpha-4 integrins?

Answer 38

The recruitment of lymphocytes and monocytes to inflammation areas

Question 39

What is Natalizumab?

Answer 39

Humanized monoclonal antibody against alpha4-integrin

Question 40

What is natalizumab used to treat?

Answer 40

Multiple sclerosis, Crohn's disease

Question 41

What type of protein does the focal contact of adherens junctions use?

Answer 41

Integrins