Lecture 22

Question 1

Association of ligands with adhesion receptors can activate intracellular signal transduction pathways, leading to changes in gene expression, cellular differentiation, secretion, motility, receptor activation, and cell division

Answer 1

sixth principle of adhesion

Question 2

links integrins to the actin cytoskeleton and bears forces exerted during motility

Answer 2

vinculin

Question 3

Many adhesion proteins bind one main ligand, and many ligands bind a single type of receptor. If this one-to-one pairing were the rule, adhesion would be simple indeed. However, many exceptions exist, particularly in the integrin family of receptors

Answer 3

second principle of adhesion

Question 4

functions in basal lamina to aid in regeneration after injury

Answer 4

molecular scaffolding

Question 5

anchors intermediate filaments in a cell to the ECM

Answer 5

hemidesmosome

Question 6

cell membrane receptor by which cells specifically recognize each other and adhere to each other

Answer 6

Cell-cell adhesion receptor

Question 7

cell membrane receptor by which cells specifically recognize cell matrix proteins and adhere to them; ex. integrins and fibronectin

Answer 7

Cell-matrix adhesion receptor

Question 8

3 steps of transendothelial migration in nervous system

Answer 8

capture and rolling, activation and adhesion, and migration

Question 9

3 functional roles of basal lamina

Answer 9

molecular filter, cell barrier, and molecular scaffolding

Question 10

class of de-adhesion factors that contain the integrin-binding RGD sequence present in many ECM proteins; competitively inhibit binding of cells to matrix components by binding to integrins. present in snake venoms, which prevent platelets from aggregating, are partly responsible for the anticoagulant property of venoms

Answer 10

disintegrins

Question 11

seals gap between epithelial cells

Answer 11

tight junction

Question 12

Many adhesion receptors interact with the cytoskeleton inside the cell

Answer 12

fifth principle of adhesion

Question 13

anchors actin filaments in cell to ECM

Answer 13

focal adhesions

Question 14

3 independent stimuli that activate platelets

Answer 14

Integrin binds to collagen on basal lamina, thrombin activates 7-helix receptors, ADP activates 7-helix receptors

Question 15

small proteins from viper venoms which function as potent inhibitors of both platelet aggregation and integrin-dependent adhesion

Answer 15

Disintegrin

Question 16

T/F: no proper adhesions of leukocytes cause problems of spread of infections

Answer 16

True

Question 17

are subcellular structures through which mechanical force and regulatory signals are transmitted between the ECM and the cell interior

Answer 17

Focal adhesion

Question 18

T/F: Cells can sort themselves out according to the type and level of cadherin they express

Answer 18

True

Question 19

is a type of cell adhesion molecule which is important in formation of adherens junctions to bind cells to each other. They are calcium dependent

Answer 19

Cadherin adhesion receptor

Question 20

use cell adhesion receptors in process of antigen presentation through clonal expansion

Answer 20

T-cells

Question 21

which attach the actin cytoskeleton to fibers of fibronectin,

Answer 21

focal adhesions,

Question 22

Cells modulate adhesion by controlling the surface density, state of aggregation, and state of activation of their adhesion receptors

Answer 22

third principle of adhesion

Question 23

most _______ bind other cell surface adhesion proteins; heterophilic

Answer 23

Ig-CAMs

Question 24

connects actin filament bundle in one cell with that in the next cell

Answer 24

adherens junction

Question 25

another class of de-adhesion factors: membrane bound proteases that catalyze shedding of transmembrane proteins. By degrading ECM matrix components, these enzymes facilitate cell migration

Answer 25

ADAMs

Question 26

connects intermediate filaments in one cell to those in the next

Answer 26

desmosome

Question 27

, is found mainly on the basal surface of epithelial cells. These junctions firmly anchor epithelial cells to the underlying basal lamina. The cytosolic side consists of a plaque composed of adapter proteins

Answer 27

hemidesmosome

Question 28

allows passage of small water-soluble molecules from cell to cell

Answer 28

gap junctions

Question 29

The rates of ligand binding and dissociation are important determinants of cellular adhesion; some cell surface adhesion proteins bind their ligands weakly

Answer 29

fourth principle of adhesion

Question 30

_____ can be spatially restricted in their expression for organization, proper space, and orientation

Answer 30

cadherins

Question 31

most ___ prefer to bind to themselves; require Ca2+

Answer 31

cadherins

Question 32

transmembrane receptors composed of heterodimeric subunits which were products of two separate genes. mediate both cell-cell and cell-ECM adhesion. One important, rapid and reversible mechanism for regulating adhesion is by increasing the affinity of integrin receptors for their extracellular ligands. This is controlled by intracellular signals that, through their action on integrin cytoplasmic domains, induce conformational changes in it extracellular domains that result in increased affinity for ligand.

Answer 32

Integrin receptors

Question 33

bind anionic polysaccharides like those on mucins; such interactions bind together 2 different types of cells

Answer 33

selectins

Question 34

, which connect intermediate filaments to basal laminae

Answer 34

hemidesmosomes

Question 35

are found in highly motile cells such as skin keratinocytes, which are weakly adherent, and in immobile, strongly adherent cells such as epithelia

Answer 35

Integrin-containing cell matrix junctions

Question 36

_______ reflects not only the level of synthesis but also the partitioning of adhesion molecules between the plasma membrane and intracellular storage compartments

Answer 36

Surface density

Question 37

functions in basal lamina in retaining proteins in blood while filtering toxic substances into the urine

Answer 37

molecular filter

Question 38

functions in basal lamina in separating ameloblasts and odontoblasts by a basement membrane during tooth development

Answer 38

cell barrier

Question 39

anchor cadherins into cell; bind to actin cytoskeleton of the cell, integrate the epithelial cells together into a mechanical unit

Answer 39

cateniin

Question 40

basically the leukocyte adhesion receptor composed of two subunits, CD18 and CD11a. Ligands include ICAM. exists in an inactive state with low affinity of ICAM and activated state with enhanced affinity for ICAM. Chemokines can stimulate the activation

Answer 40

Leukocyte function associated antigen-1

Question 41

Important in inflammation, immune responses, and intracellular signaling

Answer 41

ICAM: intercellular adhesion molecule

Question 42

very small stud-like structures found in keratinocytes of the epidermis of skin that attach to the extracellular matrix (ECM)

Answer 42

Hemidesmosome

Question 43

____ drives cell sorting of different types of cells

Answer 43

cadherin

Question 44

calcium dependent adhesion molecules, interact with each other on adjacent cells and are anchored into the cell by catenins

Answer 44

cadherins

Question 45

Cells define their capacity for adhesive interactions by selectively expressing plasma membrane receptors (cell adhesion molecules, or CAMs) with limited ligand-binding activity; expression of the proper mix of receptors is part of a genetic program for the differentiation of the cell; extracellular stimuli can control expression of adhesion receptors

Answer 45

first principle of adhesion

Question 46

stand apart because they bind to a variety of ligands

Answer 46

integrins