CAMs and Junctions

Question 1

Desmocollins and Desmogleins belong to which group of CAMs?

Answer 1

Cadherins

Question 2

Zonula occludens and Desmosomes are associated with what type of CAM?

Answer 2

Cadherins

Question 3

What serves as a major interface between the cadherins that hold adjacent cells together and their acting cytoskeletons?

Answer 3

Catenins

Question 4

________ bind molecules in the ECM such as fibronectin and laminin

Answer 4

Integrins

Question 5

__________ are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and the cells that cells that make up the tissue

Answer 5

Zonula Adherens

Question 6

_______ attach one cell to the ECM and are only associated with the basal domains

Answer 6

Hemidesmosomes

Question 7

Selectins bind to ___________

Answer 7

carbohydrates

Question 8

Fribronectin:

Answer 8

glycoprotein formed by two identical chains linked by disulfide linkages close to the c-terminal.

Question 9

Two forms of fibronectin.

Answer 9

1. Cellular fibronectin: from fibroblast, forms part of ECM

2. Plasma fibronectin: from hepatocytes, secreted into bloodstream.

Question 10

Binding sites on fibronectin: (4)

Answer 10

heparing (proteoglycan), integrins, collagen, fibrin.

Question 11

What are the types of calcium dependent CAMs?

Answer 11

cadherins, selectins

Question 12

What are the two types of calcium independent CAMs?

Answer 12

Integrins, immunoglobulin superfamily molecules

Question 13

Ligand recognized by cadherins

Answer 13

other cadherins (same or different, it don’t matter)

Question 14

Ligand recognized by selectins

Answer 14

carbohydrates

Question 15

Ligand recognized by integrins

Answer 15

extracellular matrix molecules

Question 16

Ligand recognized by Ig superfamily

Answer 16

integrins

Question 17

E-Cadherins (a classical cadherin) are found where?

Answer 17

Epithelial tissues

Question 18

N-Cadherins (a classical Cadherin) are found where?

Answer 18

Nerve cells

Question 19

P-Cadherins (a classical Cadherin) are found where?

Answer 19

Placenta.

Question 20

Desmocollins and desmogleins (nonclassical cadherins) are found where?

Answer 20

Desmosomes (macula adherens)

Question 21

_________ are the most common type of cadherins and have a __________ binding face.

Answer 21

1. E-cadherins 2. HVA (form homophilic dimers)

Question 22

A loss of __________, can be associated with invasive behavior of tumor cells.

Answer 22

e-cadherins

Question 23

__________ are small proteins that link the cytoplasmic end of a cadherin with cytoplasmic actin

Answer 23

Catenins

Question 24

Integrins have how many subunits?

Answer 24

Two

Question 25

Name the Proteins (3) that can be used to connect integrin to actin filaments

Answer 25

Talin, Vinculin, Alpha-actinin

Question 26

Give an example of intracellular tonofilaments

Answer 26

intermediate filaments such as keratin

Question 27

in hemidesmosomes, __________ link the basal domains of cells vis the intracellular tonofilaments

Answer 27

Integrins

Question 28

N-CAM

Answer 28

neural adhesion molecules.

Question 29

I-cam-1 and I-cam-2

Answer 29

I-CAM-1 facilitates transendothelial migration of leukocytes

Question 30

Adherens

Answer 30

are molecular complexes that anchor cell together and reinforce the physical integrity of tissues and the cells that make up the tissues.

Question 31

Occludens

Answer 31

molecular complexes that establish and impermeable barrier between adjacent cells, especially epithelial cells, that prevents paracellular transport and maintains concentration differences btwn the environments on either site of the epithelial sheets.

Question 32

Gap Junctions

Answer 32

composed of molecular pores that enable cells to rapidly exchange ions and small molecules that help coordinate activities among the cells that make up the tissue.

Question 33

Types of Junctions: Zonula:

Answer 33

either adherens or occuldens variety, Zonula complexes travel all the way around the cell and link all neighboring cells to this central cell. (associated with intracellular actin)

Question 34

Types of junctions: Macula:

Answer 34

"spot" or snap-like junction. Adherens variety and are often referred to as desmosomes (lateral domains of epithelial cells) or hemidesmosomes (basal domain of epithelial cells). Macula are associated with (tonofilaments) intermediate filaments)

Question 35

Cadherin proteins are anchored to cytoplasmic plaques containing:

Answer 35

Desmoplakin, Plakoglobin

Question 36

Zonula and macula adherens are mediated by interations with __________ and __________ cadherins

Answer 36

desmocollins, desmogleins

Question 37

A hemidesmosome consist of

Answer 37

a cytoplasmic plate associated with intermediate filaments such as keratin. A membrance plaque linking it to the basement membrane.

Question 38

Zonula occludens

Answer 38

are tight, belt-like occluding junctions. Provide a great barrier against the paracellular transport pathway. Other transmemebrane proteins include junctional adhesion molecules (JAMs) and Nectin.

Question 39

Nectin:

Answer 39

is associated with the intracellular molecule, afadin

Question 40

JAMs

Answer 40

are associated with both afadin and ZO-1

Question 41

JAMs and Nectin:

Answer 41

are members of the immunoglobulin superfamily. stabilized by disulfide bonds and for cis-homodimers that facilitate cell adhesion.

Question 42

Gap junctions are composed of _____________

Answer 42

Connexons

Question 43

Each connexon, consist of __ __________, formaing a hexagonal structure with a ___________.

Answer 43

6 connexins, hollow center.

Question 44

Gap junctions close when __________ ________ concentrations are high.

Answer 44

calcium Ion