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Cell-Cell and Cell-Matrix Interactions
Muehleman
16
Biochemistry
Professional
10/09/2011

Additional Biochemistry Flashcards

 


 

Cards

Term

 

 

 

 

Extracellular Matrix (ECM) functions

Definition

holds tissue together

strength (bone)

elasticity (cartilage)

cushioning (cartilage)

adhesion

envt cues to cells

modulates cell-envt interaction

surface on which cell mvt can occur

reservoir for extracellular signalling molecs

Term

 

 

ECM components (4)

Definition

 

 

collagen

elastin

proteoglycans

multiadhesive matrix proteins

Term

 

 

 

fibronectin

Definition

 

multiadhesive matrix protein

 

glycoprotein that binds to integrins and other ECM components

Term

 

 

 

 

laminin

Definition

multiadhesive matrix protein

 

major protein of ECM and basement membrane

Term

 

 

 

perlecan

Definition

 

 

multiadhesive matrix protein

 

proteoglycan that binds and crosslinks many ECM and cell surface molecs

Term

 

 

 

 

Cell-adhesion molecules (CAMs)

Definition

 

 

cadherins, selectins, integrins, immunoglobulins

 

intercellular and cell-matrix interactions

Term

 

 

 

 

cadherins

Definition

calcium-dependent glycoproteins, mediate homocytic and heterocytic adhesive interactions

 

intracellular, transmembrane, and intercellular domains

 

adhesion can be tight or weak

 

adapter proteins link cadherins to cytoskeleoton, recruit signaling molecules (ex: alpha and beta catenin)

Term

 

 

 

cadherins and cancer

Definition

breast cancer metastasis

 

1. down-regulation of E cadherin-->dec intercell. adhesion strength-->inc cellular motility (cancer cells can cross basement memb)

2. loss of E cadherin--> E-cadherin-catenin complex degrades, release of signal molecs related to invasiveness

3. N-cadherin (not normally present) upregulated w loss of E cadherin-->tumor growth

Term

 

 

 

Selectins

Definition

 

 

calcium-dependent vascular adhesion molecules produced by endothelial cells

 

interactions btw endothelium, leukocytes, inflammatory process

 

E-selectin, P-selectin, L-selectin

Term

 

 

 

selectin response

Definition

 

foreign substance activates macrophages, cytokines stim endothelial cells, which produce selectins

 

E & P selectins slow down leukocytes, leading to recruitment.  Leukocytes then enter infected site (extravasation)

Term

 

 

 

E-selectin and breast cancer

Definition

 

 

overexpression: more positive lymph node metastasis

 

down-regulation: reduction in adhesion (inc motility)

Term

 

 

 

integrins

Definition

transmembrane receptors for ECM components

 

extracellular, transmembrane and intracellular components

 

attach to intracellular adapter proteins -- cell growth/motility

 

bidirectional signal capabilities--transmit biochemical signals as well as mechanical force

Term

 

 

 

 

intercellular adhesion molecule (ICAM-1)

Definition

 member of immunoglobulin superfamily

 

when E and P selectins slow down leukocytes at site of infection, ICAM-1 carries out tighter adhesion function, stopping leukocytes by binding to leukocyte integrins

 

facilitates extravasation

Term

 

 

 

leukocyte adhesion deficiency

Definition

 

 

genetic defect in synthesis of integrin subunit

 

susceptible to repeated bacterial infections and non-healing wounds bc leukocytes cannot extravasate, migrate or phagocytose properly

Term

 

 

 

 

integrins and cancer

Definition

 

 

integrin activation down-regulates E-cadherin, allowing cancer cells to cross basement memb

 

integrin modulates expression of MMPs which break down matrix components, allowing cancer cells in

 

VEGF (vascular endothelial growth factor) stimulates vasculature at tumor site

Term

 

 

 

 

pemphigus

Definition

 

 

antibodies form against ECM laminin or integrin

 

blistering of skin

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