Cell Adhesion Flashcards Preview

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Flashcards in Cell Adhesion Deck (41)
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1
Q

What molecules are involved with cell-cell adhesions?

A

Cadherins

Integrins

2
Q

What are the functions of cell-cell communication?

A
WOund healing
Inflammation
Immune response
Tumor metastasis
BLood clotting
Growth
3
Q

Is cell adherence reversible?

A

Yes

Specific and reversible

4
Q

What are the types of adhesion?

A
Homotypic adhesion (similar cells)
Heterotypic adhesion (Dissimilar cells)
5
Q

What is an example of a hetertypic adhesion

A

Neuron and schwann cell

6
Q

What are N-CAMs?

A

Neural Adhesion molecule

7
Q

Where are cadherins found?

A

Plasma membrane

8
Q

What moelcule do cadherins need to function?

A

Calcium allows interaction with neighboring cell via cadherins

9
Q

What type of side chains do cadherins have?

A

Carbohydrate side chains

10
Q

What type of junction do cadherins bind through?

A

Adherens junctions with Actin cytoskeleton & desmosomes

11
Q

What are Integrins

A

Linker proteins

12
Q

What is a benefit of integrins

A

Binding is weak with low affinity which allows cells to migrate

13
Q

What is the organization of cell adhesion?

A
  1. Cytoskeletal element (Actin)
  2. Adaptor proteins
  3. Transmembrane adhesion proteins (Fibronectin)
  4. Extracellular ligands (COllagen)
14
Q

What are the types of cell junctions?

A

Adhesive (Desmosome, hemidesmosome, adherens junctions)

Tight junctions

Gap junctions

15
Q

WHat is the purpose of adhesive junctions?

A

Connect cytoskeleton to cytoskeleton

Allows cells to function as a unit

16
Q

What types of cells are adhesive junctions most common in?

A

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

17
Q

What types of proteins to adhesive junction contain?

A

Intracellular attachment proteins

Transmembrane linker proteins

18
Q

What are intracellular attachment proteins?

A

Located inside plasma membrane

Forms thick plaque on cytoplasmic side

19
Q

What are transmembrane linker proteins?

A

Located outside plasma membane

Binds cells to ECM

20
Q

What tissues are desmosomes often found?

A

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

21
Q

What is the desmosome made of?

A

Junctional complex

Cadherins, integrating membranes, transmembrane linker proteins

22
Q

What is the function of the hemidesmosome?

A

Connects Epithelial cell to basal membrane using Integrins (laminins)

23
Q

What are adhesive junctions?

A

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

24
Q

Where are adhesive junctions found?

A

Layers of tissue that line body cavities

25
Q

What is a gap junction?

A

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

26
Q

WHat is Zonula occludens protein-1

A

Major tight junction structural protein

27
Q

What is the most common junction?

A

Gap Junction

28
Q

Where are Gap junctions most commonly found?

A

In all cells
Specifically cells requiring simultaneous reaction:
Muscle
Nerve

29
Q

Is there space between tight junctions?

A

No

30
Q

What are the tightest junctions of the body?

A

Epithelial cells of inner ear

Blood-brain barrier

31
Q

What are the major types of proteins in tight junctions?

A

Claudins, occuludins

32
Q

What do tight junctions bind?

A

Cytoskeleton to adjacent cells

33
Q

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

A

Desmosome
Adhesion belt
Tight junction

34
Q

What is Pemphigus?

A

Auto-immune disease that attacks Cadherins

Causes skin to fall off

35
Q

What is the treatment for Pemphigus?

A

Corticosteroid injections

36
Q

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

A

Dsg3
Dsc1
Dsg1

37
Q

What is the most common type of Pephigus?

A

Pemphigus foliaceus

38
Q

What is the importance of alpha-4 integrins?

A

The recruitment of lymphocytes and monocytes to inflammation areas

39
Q

What is Natalizumab?

A

Humanized monoclonal antibody against alpha4-integrin

40
Q

What is natalizumab used to treat?

A

Multiple sclerosis, Crohn’s disease

41
Q

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

A

Integrins