ecm cell adhesion molecules

Interaction of cells with the environment

Unit Outline:

What is outside the cell and how do cells communicate with what’s “out there”?

How do cells interact with their external environment?

How do cells interact with each other?

Extracellular space

Extracellular space

basal surface of ectodermal cell of chick embryo

apical surface of epithelial

cell from intestinal

lining

Extracellular matrix

epidermis pulled away from basement membrane

basement membrane

between blood vessels of

glomerus and renal tubules

collagen

Extracellular matrix

Extracellular matrix

Proteins of ECM - collagen

Extracellular matrix

Proteins of ECM - proteoglycans

Extracellular matrix

Proteins of ECM -

fibronectin

Extracellular matrix

Proteins of ECM - laminin

collagen

laminin

Interaction of cells with ECM

inactive

INTEGRINS

Interaction of cells with ECM

INTEGRINS

functions of outside-in signals

differentiationmotilitygrowth survival

ligands have RGD

motif

Interaction of cells with ECM

FOCAL ADHESIONS

FA

Interaction of cells with ECM

FOCAL ADHESION

S

Interaction of cells with ECM

HEMIDESMOSOMES

Interaction of cells with ECM

Interaction of cells with cells

CELL ADHESION MOLECULES

Interaction of cells with cells

CELL ADHESION MOLECULES

Interaction of cells with cells

CELL ADHESION MOLECULES

Interaction of cells with ECM and other

cells

CELL ADHESION MOLECULES VS

ECM ATTACHMENT MOLECULES

vocabularyextracellular spaceextracellular matrixbasement membraneglycocalyxcollagenfibronectinproteoglycanGAG chainslaminininside-out signalingoutside-in signalingfocal adhesionfocal adhesion kinase (FAK)actin keratin

talinvinculinactininhemidesmosomecell adhesion moleculeselectinlectinImmunoglobulin superfamilycadherintight junctionadherins junctiondesmosomegap junction

Extracellular Matrix Unit Learning Goals:the extracellular space:

a. discuss the concept that the physical interactions between cells and their extracellular environment is highly specific as a result of molecular interactions between molecules on the cell with molecules in the matrix between cells and molecules on neighboring cells

b. describe the molecular components of the extracellular matrix (ECM) and discuss the cellular processes regulated by interactions between cells and their extracellular environment

interaction of cells with ECM:

a. compare the structure, function and signaling activity of integrins and “true” ECM proteins like collagen, laminin, and proteoglycans

b. comapre the structure and functions of molecular structures formed at the site of attachment of cells to an artificial substrate (focal adhesion) and to the basement membrane (hemidesmosome)

interaction of cells with other cells:

a. describe the general class of proteins mediating interactions between cells (cell adhesion molecules) using specific examples

b. compare the functions of cell adhesion molecules and extracellular matrix attachment molecules

c. discuss why insoluble solutes, whch cannot freely diffuse through the plasma membrane, also cannot pass freely between cells of an epithelial layer, and what would happen to tissues of they could

d. compare tight junctions, adherins junctions, desmosomes, and gap junctions in terms of structure, function and the type of cells in which they are found

e. draw, in cross section, two neighboring epithelial cells and illustrate the relative location and general structure of adherins junctions, desmosomes, tight junctions and gap junctions