Cell Junctions And Adhesions

Question 1

Tight Junctions

Answer 1

Encircle entire cell like a belt

Actively regulate permeability of small molecules

Question 2

Mutation in Claudine lead to

Answer 2

Kidney calcification

Deficient Ca and K reuptake

Question 3

Belt desmosomes

Answer 3

Encircle entire cell, right below tight junctions

Question 4

Tight junctions are linked to _______ cytoskeleton by _______

Answer 4

Actin

Adaptor proteins

Question 5

Belt desmosomes connected to _______ cytoskeleton by ______

Answer 5

Actin

Catenins

Question 6

E Cadherin

Answer 6

Present in belt desmosomes

Important for cell-cell adhesion

Question 7

P cadherin

Answer 7

In belt desmosomes
Selectively distributed (retina, hair follicles)

Question 8

Spot desmosomes

Answer 8

Spot like cell-cell junctions

Question 9

Spot desmosomes are linked to _______ Cytoskeleton by _______

Answer 9

Intermediate filaments

Adaptors (desmoplakin, plakoglobin, plakophilin)

Question 10

Integrins interact with ________ on __________-

Answer 10

ECM proteins

RGD sequence

Question 11

Integrins

Answer 11

Present in actin-linked cell-matrix adhesion sites (focal adhesions)
Transmembrane protein (alpha/beta subunit)

Question 12

Hemidesmosome

Answer 12

Interaction between cells and basement membrane
Mechanical strength
Cell anchorage

Question 13

Focal adhesions

Answer 13

Important for cell migration

Question 14

Gap junctions

Answer 14

Coordinate cellular responses

Question 15

Connexon channels

Answer 15

Allow small molecules to pass cell-cell
Permeability is regulated
Formed by 6 connexin proteins

Question 16

Selections

Answer 16

Transmembrane proteins that are Ca dependent
Bind oligosaccharides
Role in inflammation

Question 17

Immunoglobulin superfamily

Answer 17

Do NOT need Ca

It-like domain on extracellular side

Question 18

Connexin 26 mutation

Answer 18

Leads to deafness

In cochlear hair cells

Question 19

Connexin 32 mutation

Answer 19

Leads to peripheral neuropathy

In myelin

Question 20

Steps to Leukocyte Extravasation (4)

Answer 20

1. Leuk. Slows down and starts rolling due to loose adhesion with selectins on surface
2. Integrins activated on leuk. That bind to ICAM/VCAM on endothelial cells
3. Leuk. Stops bc strong adhesive forces
4. Integrin-mediated migration btwn endothelial cells (through blood vessel wall)