ECM Flashcards
define ECM
network of macromolecules that occupy the extracellular space
what makes the ECM
connective tissue/cell
functions of ECM
protect
support
strength
signal
what does the ECM store
growth factors
what is the ECM used for
cell adhesion/migration
what occurs with malignant cells
continue to grow without ECM or connection with other cells
what happens when cells do not have ECM
programmed cell death by anoikis
ECM proteins 6
collagen elastin fibronectin laminin proteoglycans minerals
how is elastin secreted
soluble formed linked by disulphide bridges
what is fibronectin
large protein or 2 almsot identical protein (dimer)
functions of fibronectin
support and strength
interactions with other ECM proteins
fucntio of laminin
binding site for cell/protiens
what is laminin a component of
basal lamina
what is the basal lamina
layer of the basement membrane
what are proteoglycans
protein backbone with polysaccharide side chains
what do proteoglycans do
regulate protein activity and act as co receptors
what are the side chains of proteoglycans called
glycosaminoglycans
what is the basement membrane
network of macromolecules
specilaised form of ECM
how do cells interact with the ECM
through integrins
what are integrins
membrane bound receptros
what are integrins made of
2 different protiens (heterodimer)
what determins ligand binding
specific dimer pairing
purpose of integrins 2
cells can detect what matrix they are bound to
generates a signal once bound
how do cells modify the ECM
secrete proteilytic enzymes to break down ECM allowing path for cell migration
what acts as a signal after ECM has been broken down
degradation productis
what can enzymes do in responce to degradation products
secrete/activate GF
What occurs at wound heeling
matrix signals
haemostat responce to prevent bleeding
cells move and proliferate at wound
what is different in canner
matrix and integrin expression
what does integrin signal for
growth
apoptosis
migration
what is connective tissue called in cancer
stroma
what happens during tutor metastasis
disregulated growth, decreased cell contact
basement membrane breaks down
timor cells invade stroma
regrow with angiogenesis
how can the ECM vary
due to different composition
what are elastic fibres arrangement and components
cross linked arrays of tropoelastin
what is laminin
large protein of 3 different subunits
function of laminin
binding site for cells/protein
what does laminin signal cells to do
differentiate
adhere
migrate
what can integrins also act as
mechanosensors
