Extracellular Matrix and Adhesion Flashcards Preview

M2M Unit III > Extracellular Matrix and Adhesion > Flashcards

Flashcards in Extracellular Matrix and Adhesion Deck (10):
1

Functions of ECM (6)

Scaffolding
Regulates Cell Survival (Integrins)
Differentiation
Migration (GAGs)
Proliferation
Shape

2

Four major components of ECM

Glucosaminoglycans
Proteoglycans
Fibrous Proteins: Collagen and Elastin
Multidomain Adaptor proteins: Fibronectin & Laminin

3

Glucosaminoglycans

repeated disaccharides that can attach to serine residues through a tetrasaccharide linker.
Acetylation/Sulfation determines type of GAG
Cross-linking helps with ECM structure
Can bind signals (usually inactive when bound) such as selectins for leukocyte extravasation

4

Collagen

Most abundant protein in body, main ECM component
Different collagens have different properties
Coiled trimer = pro-collagen, termini removed = tropo collagen
Provide scaffolding

5

Fibronetin/Laminin

Signaling molecules in ECM, multimers that change ECM properties
Fibronectin: dimer formed by C terminus disulphide bridge. Self association and collagen, cell, and heparin binding domains to maximize cross linking
Laminin: Heterotetramer w/ multiple cross-linking chains/domains

6

MMPs

Actin protrusions at leading edge coupled with myosin provides movement.
MMPs are zinc-dependent, inactive w/ C terminus attached. Secreted into ECM where C terminus is cleaved and they degrade ECM and activate signals associated with GAGs

7

Adhesion and Cell Survival

Cells require binding to ECM via integrins in order to survive.

8

Integrins

transmembrane heterodimers of alpha and beta subunits that recognize specific ECM proteins
Beta unit binds actin intracellularly via adaptor proteins, important in cell motility.
Promote survival and suppress apoptosis when bound to ECM, opposite when not bound to ECM

9

Cadherins

calcium dependent homodimers that create junctions between cells.
Bind actin intracellularly via beta catenin

10

CAMs and signaling

Rho associated with CAMs, Beta catenin with cadherins