Lecture 8: Cells in their environment

Question 1

__ connect cells with their neighbors

Answer 1

keratin filaments

Question 2

Desmosome

Answer 2

a cadherin keratin structure that links intermediate filaments with neighboring cells and ECM

Question 3

anchor proteins

Answer 3

linking cadherins with keratin filaments

Question 4

keratin filament

Answer 4

-link neighboring cells at desmosomes
=link cells to the ECM at hemi-desmosomes

Question 5

What do keratin gene mutations cause?

Answer 5

blistering of skin (Epidermolysis bullosa simplex)

Question 6

The organization of an epithelial layer by

Answer 6

numerous cell junctions

Question 7

IF based

Answer 7

-desmosomes (cell-cell)
-hemi-desmosomes (cell-ECM)

Question 8

Actin based

Answer 8

• adherens junction (cell-cell)
• focal adhesion (cell-ECM)

Question 9

Adherens junctions

Answer 9

cadherins link active filaments between adjacent cells – E cadherin and actin

Question 10

Cadherin binds to __ via specific actin binding proteins

Answer 10

F-actin

Question 11

Cadherins connect the __ __ between neighboring cells

Answer 11

cytoskeletal elements

Question 12

Ca 2+ maintains the correct _ and _ between cadherins of two cells

Answer 12

orientation, interactions

Question 13

What is the ECM

Answer 13

Extracellular Matrix
-collection of extracellular molecules secreted by fibroblasts
-varies between different tissue
-provides structural support
-contains insoluble fibers

Question 14

what is a critical component of ECM?

Answer 14

collagen

Question 15

How do cells attach to ECM?

Answer 15

Integrins (cell-ECM)

Question 16

What do integrins do?

Answer 16

Link the cytoskeleton to the ECM

Question 17

Integrins undergo what?

Answer 17

A switch between active and inactive state

Question 18

What is the signal across the membrane by integrins?

Answer 18

Bi-directional regulation

Question 19

Collagen mutations

Answer 19

fibronectin and laminin proteins