Andersen lecture

Question 1

What are the 2 calcium dependent CAMS

Answer 1

selectin and cadherin

Question 2

What are the 2 calcium independent CAMS

Answer 2

interns and immunoglobulin superfamily molecules

Question 3

Describe the adherens junction in terms of…

1. transmembrane protein
2. extracellular ligand
3. intracellular cytoskeletal attachment
4. intracellular anchor protein

Answer 3

1. cadherin (classical)
2. ligand- cadherin in the neighboring cell
3. attachment- actin filaments
4. alpha and beta catenin, plakyglobin

Question 4

Describe the desmosome in terms of…

1. transmembrane protein
2. extracellular ligand
3. intracellular cytoskeletal attachment
4. intracellular anchor protein

Answer 4

1. cadherin (non-classical)
2. desmoglein and desmocollin in the neighboring cell
3. intermediate filaments
4. plakoglobin

Question 5

Describe the actin-linked-cell matrix adhesion in terms of…

1. transmembrane protein
2. extracellular ligand
3. intracellular cytoskeletal attachment
4. intracellular anchor protein

Answer 5

1. integrin
2. ECM proteins
3. actin
4. tallin, alpha actin, etc

Question 6

Describe the hemidesmosome in terms of…

1. transmembrane protein
2. extracellular ligand
3. intracellular cytoskeletal attachment
4. intracellular anchor protein

Answer 6

1. integrin and type XVII collagen
2. ECM proteins
3. intermediate filaments
4. pectin, dystonin

Question 7

What are the stable junctions of cadherins?

Answer 7

occludens and desmosomes

Question 8

What are the stable junctions of integrins?

Answer 8

hemidesmosomes

Question 9

What are the classical cadherins?

Answer 9

E N and P
epithelial
nerve
placenta

Question 10

What are the nonclassical cadherins?

Answer 10

desmocollins and desmogleins

found in desmosomes

Question 11

What are the differences between the intra and extracellular portions of the cadherins?

Answer 11

extracellular has multiple copies of the cadherin domain motif
intracellular proteins are varied and they can interact with a number of the components

Question 12

What type of binding is usually found between cadherins? homophilic or heterophilic?

Answer 12

homophilic

Question 13

On what terminus dies the homophilic binding occur?

Answer 13

N terminus

Question 14

What happens to the extracellular domain of the cadherin when calcium binds to the sites near the hinge?

Answer 14

It straightens all of the molecules out

Question 15

What happens when the calcium is removed from the “hinge” region of the molecule

Answer 15

It becomes floppy and they are usually degraded from there

Question 16

What makes the cadherin molecular bonds relatively strong?

Answer 16

It is a series of weak interactions that come together to form a type of “velcro”

Question 17

Define sorting out in relation to the cadherin mediated adhesion

Answer 17

enables cells that are similar to bind to each other and not to molecules that are different from them

Question 18

Describe the process of a cell altering its adhesive properties to form different cell types?

Answer 18

some cells change properties and disengage from the surface of the epithelium to form the neural crest
cells migrate away and they form different cells throughout the body

Question 19

What is the function of a catenin?

Answer 19

cadherins to the actin of the neighboring cells

Question 20

What are e cadherins?

Answer 20

epithelial cadherins; HVA binding face

Question 21

What do selectins bind to?

Answer 21

carbohydrates look for the binding site at the CRD

Question 22

What cellular process do the selectins aid with?

Answer 22

movement of leukocytes

Question 23

What are the 3 classes of selectins?

Answer 23

E- endothelial cells
L- leukocytes
P- platelets

Question 24

Define integrins

Answer 24

glycoproteins that are involved in the ECM interactions (fibronectin and laminin)
2 subunits: alpha and beta

Question 25

Ig superfamily NCAM

Answer 25

neural adhesion molecules | mediate homophilic and heterophilic interactions

Question 26

Ig superfamily ICAM 1

Answer 26

facilitates trans endothelial migration of leukocytes

Question 27

define adherins and state where they are found on the surfaces of the cells

Answer 27

anchor cells tighter and maintain the physical integrity of the cells basolateral surfaces

Question 28

Define occludens

Answer 28

create an impermeable barrier and prevent paracellular transport

Question 29

Define gap junctions

Answer 29

junctional complex that has molecular pores that enable rapid exchange of molecules

Question 30

Define zonula

Answer 30

travel all the way around the circumference of the cell; associated with the intracellular actin can be adherents and the occludens variety

Question 31

Define macula

Answer 31

spot like junction that are usually found in desmosomes and hemidesmosomes

Question 32

What surface are the desmosomes found on?

Answer 32

lateral domain

Question 33

What surface are the hemidesmosomes found on?

Answer 33

basal domain

Question 34

What molecules are found adjacent to the adherens "adhesion belt"?

Answer 34

actin filaments

Question 35

Define desmosome

Answer 35

connects the intermediate filaments in one cell to those in the next mechanical strength button like spots

Question 36

What is the structure of a desmosome?

Answer 36

cytoplasmic surface- dense plaque composed of anchor proteins keratin filaments on the plaques cadherins bind to the plaques and hold everything together

Question 37

Define hemidesmosomes

Answer 37

anchoring junctions that anchor the basal domain to the basal lamina

Question 38

What is the structure of a hemidesmosome?

Answer 38

cytoplasmic plate with the intermediate filaments like keratin plaque linking to the basal lamina

Question 39

define tight junction

Answer 39

seals everything off | is important in the small intestine and the glucose transport

Question 40

What are the 2 main tight junction proteins?

Answer 40

claudin and occludin claudin is the main guy