Cell Adhesion 4 - Adhesion on behaviour Flashcards
1
Q
What is compaction?
A
- hallmark event of 8 cell stage in mouse embryo developement
- when you can no longer see the intercellular boundaries as adhering junctions form
- E-cadherin is essential for formation of adhering here
- found mainly on basolateral cell-cell contact sites
2
Q
Where is E-cadherin mainly found during compaction?
A
Basolateral cell-cell contact sites
3
Q
Describe 2 experiments defining cadherin-mediated adhesion
A
- adhesion-blocking antibodies - exposure to anti-cadherin antibodies causes embryo to fall apart
- expression and deletion of cadherin - mutant embryos lacking E-cadherin fall apart
4
Q
Explain loss and gain of function mutations
A
- if you remove what you think is causing the effect, does the effect still happen?
- when the feature is back does it function again?
5
Q
name 3 different types of cadherins?
A
- E-cadherin
- R-cadherin
- Cadherin-6
6
Q
Where is E-cadherin expressed in the embryo?
A
- mainly in epithelial cells
7
Q
Where is R-cadherin and N-cadherin mainly expressed?
A
nerve, muscle and lens cells
8
Q
Where is P-cadherin expressed in the embryo?
A
- placenta
- epidermis
9
Q
Where is Cadherin-6 expressed?
A
??
10
Q
What is homopihilic binding?
A
- 2 molecules that are identical on different cells bind
11
Q
What is heterophilic binding?
A
two molecules that are different on different cells bind
12
Q
Explain homophobic binding in cadherin
A
- happens at the N-terminus - furthest point from the membrane
- Ca2+ is required or hinge would be floppy
- Changes conformation of the N-terminus
13
Q
Explain overall connections of cadherins
A
- individual interactions are relatively weak
- combination is strong
- important as cell-cell interactions commonly break and re-from during embryonic development
