Cell Adhesion

Question 1

what is cell adhesion

Answer 1

Question 2

What would happen if there was no cell adhesion and why is cell adhesion needed

Answer 2

Needed for cell recognition and tissue formation
Also needed for cell organisation, resistance and strength, barrier formation, communication with surrounding cells and the ECM

Question 3

What effects can cell adhesion have on a cell

Answer 3

Question 4

What is cell adhesion involved in

Answer 4

Question 5

How is cell adhesion involved in multicellularity

Answer 5

Question 6

What are the 4 different types of adhesion structures

Answer 6

Question 7

What is the basic structure of the epithelia

Answer 7

Question 8

Label the different parts of this cell junction in epithelia

Answer 8

Question 9

What are homophilic interactions and why are they useful

Answer 9

one type of adhesion molecule will only adhere to the same type of adhesion molecule
E.g cadherins on one cell interact with cadherins on another cell
Useful as it helps cells of the same type to stick together which helps form tissue

Question 10

What are heterophillic interactions

Answer 10

One type of adhesion molecule will interact with a different type of adhesion molecule

Question 11

What are the characteristics of desmosomes

Answer 11

are specialized cell structures that function primarily to provide strong adhesion between cells in tissues that experience considerable mechanical stress, such as the skin, heart, and certain epithelial tissues

Uses desmosomal cadherins for adhesion
Attached to intermediate filaments
Used for strength, durability and signalling

Question 12

What are the characteristics of adherens junctions

Answer 12

Cell to cell adhesion
Cadherins used for adhesion
Attatched to actin filaments
Used for shape, tension and signalling

Question 13

What are the characteristics of hemidesmosomes

Answer 13

Adhesion between cell and ECM
Integrin used for adhesion
Attached to intermediate filaments
Used for shape, rigidity and signalling

Question 14

What is the structure of an adheren junction

Answer 14

Question 15

What is the structure of desmosomes

Answer 15

Question 16

Which cell adhesion molecules undergo homophillic interactions

Answer 16

Cadherins (E-cadherins)
CAMs (cell adhesion molecules)

Question 17

Which cell adhesion molecules undergo heterophillic interactions

Answer 17

Integrins
Selectins

Question 18

What is the structure of a classical cadherin polypeptide

Answer 18

Blue= cadherin domain

Question 19

How do cadherins on one cell bind to cadherins on another cell

Answer 19

Question 20

What is the function of calcium in cadherins

Answer 20

Question 21

What are the 4 types of classical cadherins q

Answer 21

Question 22

Where are the main location of the classical cadherins

Answer 22

Question 23

What happens if the 4 types of cadherins are inactivated in mice (E, N, P and VE respectively)

Answer 23

Question 24

What is a characteristic of cell adhesion

Answer 24

It’s dynamic
Adhesion protein gene expression changes over time and adhesions assemble and disassemble

Question 25

At is an adherin junction

Answer 25

Question 26

How do adherens work and what do they do

Answer 26

‘

Question 27

What is the function of adherens

Answer 27

Question 28

What can changes in cell adhesion do

Answer 28

Question 29

What is integrin and how does its structure relate to its function

Answer 29

Question 30

How does integrin interact with the cell and the ECM

Answer 30

Question 31

Give some examples of integrins and the ligand it binds to

Answer 31

Question 32

What is the phenotype when the alpha subunit of each type of integrin is mutated, respective to this order:

Answer 32

Question 33

What is the phenotype when the beta subunit of each type of integrin is mutated, respective to this order:

Answer 33

Question 34

How can integrin be activated

Answer 34

Integrin can be activated from two directions, from the inside by the regulated binding of proteins to the cytoplasmic tails, and from the outside by multivalent ligand binding

Question 35

What happens when an extra cellular ligand binds to integrin

Answer 35

Question 36

Label the different parts of integrin on this diagram

Answer 36

Question 37

How can integrin be activated ‘inside-out’ (activated from the inside)

Answer 37

Question 38

What are igCAMS

Answer 38

Question 39

What is the function of Ig-CAMS

Answer 39

Question 40

What is the structure of Ig-CAMS

Answer 40

Orange = type III fibronectin repeat Green= Ig domain

Question 41

What is the structure of integrins

Answer 41

Blue= cadherin domain Red= lectin domain Orange= type III fibronectin repeat

Question 42

What is the structure of selectins

Answer 42

Red= lectin domain Orange= type III fibronectin repeat

Question 43

What is the function of selectins

Answer 43

Question 44

What are transient interactions

Answer 44

involve protein interactions that are formed and broken easily

Question 45

What is blood rolling

Answer 45

Leukocyte rolling describes the low affinity adhesive interaction between leukocytes and the vascular endothelium whereby the force of blood flow induces a rotational motion (i.e., rolling) of the leukocyte along the vascular wall.

Question 46

How are selectins involved in blood rolling

Answer 46

selectins mediate leukocyte capture and rolling along the vessel wall whereas interactions between integrins and Ig superfamily members arrest rolling cells and mediate firm adhesion