Lecture 5 Learning Objectives

Question 1

Two components of the basement membrane and origins

Answer 1

Basal Lamina - epithelial origins

Reticular Lamina - connective tissue origins

Question 2

List the components of the basal lamina and identify the type of collagen associated with it

Answer 2

Laminin: major component and has alpha, beta and gamma subunits
Has binding sites for integrins, type IV collagen, entactin and proteoglycans
FIbronectin: protein made up of two polypeptide chains cross-linked by disulfide bonds

Question 3

Laminin

Answer 3

Major component of basal lamina
Alpha, beta, and gamma subunits
Binding sites for integrins, type 4 collagen, entactin and proteoglycans

Question 4

Characteristics of fibronectin

Answer 4

Made up of two polypeptide chains cross-linked by disulfide bonds
Cellular and plasma forms
Binds to Heparin, Integrins, Collagen, Fibrin

Question 5

Calcium dependent CAM

Answer 5

Cadherins and Selectins

Question 6

Calcium-independent CAMs

Answer 6

Integrins and IG superfamily molecules

Question 7

Identify the three classes of Cadherins

Answer 7

E-Cadherins - epithelial
N- Cadherins - Nerve cells
P - Cadherins - placenta

Question 8

Types of nonclassical Cadherins

Answer 8

Desmocollins and desmogleins

Desmosomes

Question 9

Loss of this type of molecule is associated with invasive behavior (metastasis) of tumor cells

Answer 9

E-Cadherins

Question 10

What do lectin groups bind

Answer 10

Carbohydrates

Question 11

Selectins are involved in what type of cellular activity

Answer 11

Extravasation of leukocytes from blood to tissue

Question 12

Selectins

Answer 12

Classified as lectins because they bind to carbs
Extravasation
Carbohydrate recognition domain and calcium binding site

Question 13

Describe major function of integrins

Answer 13

Cell-to-extracellular matrix junctions

Bind to cytoskeleton and extracellular matrix

Question 14

Three categories of junctional complexes

Answer 14

Adherens
Occludens
Gap Junctions

Question 15

Adherens

Answer 15

Major complexes that anchor cells together and reinforce the physical integrity of tissues (Basolateral domain)

Question 16

Occludens

Answer 16

Establish an impermeable barrier between adjacent cells

Question 17

Gap Junctions

Answer 17

Molecular pores that enable cells to rapidly exchange ions and small molecules to coordinate activity

Question 18

Catenins

Answer 18

Serve as a major interface between the cadherins that hold adjacent cells together and the actin cytoskeleton of those cells

Question 19

Zonula

Answer 19

Complexes that travel all the way around the cell
Belt-like complexes
Can be occluden or adherens

Question 20

Macula

Answer 20

Spot or “snap” junction
adherens variety
desmosomes or hemidesmosomes (tonofilaments too)

Question 21

Afadin

Answer 21

nectin (extracellular

Question 22

Catenin

Answer 22

cadherins (extracellular)

Question 23

plaques

Answer 23

desmoplakin, plakoglobin, plakophilin

Question 24

Hemidesmosome

Answer 24

anchoring juncitons that hold basal domain of epithelial cell to basal lamina
Cytoplasmic plate on a plaque held on by int. filaments

Question 25

Zonula occludens

Answer 25

belt like
Provide barrier against paracellular transport
JAMS and nectins
Afadin

Question 26

Gap junction

Answer 26

communicating junction that allows cells to directly communicate
Formed with connexons - hexagonal structure of 6 subunits with hollow center

Question 27

Pemphigus foliaceus

Answer 27

autoantibody mediated blistering disease in which antibodies against desmoglein 1 cause a loss of adhesion of keratinocytes in the superficial layers of the epidermis