junctions Flashcards
tight junctions
- define polarity
- control passage of substances
- can link actin to cytoskleton
what are tight junctions made of?
claudins and occludin proteins
adherens junctions?
- plaque anchors the actin filaments at the membrane
- different cadherin proteins will provide cell adhesion in different tissues
E-cadherin
epithelia
adherens junctions
N-cadherin
neurons and heart muscle
p-cadherin
placenta an epidermis
VE- cadherin
endothelial cells
in adherens junctions, what does cadherins link to actin via?
catenin
what are the 2 things that make up a desmesome?
plaque and filaments
desmesome plaque?
cytoplasmic dense plaque containing desmoplakin and plakoglobin proteins
desmosome filaments?
keratin filaments anchored to the cytoplasmic dense plaque.
What does focal adhesions link the outside of the cell with the cytoskeleton via?
transmembrane proteins called integrins
what are integrins
they are proteins that bridge the gap between the cytosol and the ECM
in duchennes muscular dystrophy, what is there are absence of?
dystrophin adaptor due to premature termination of translation
how does microinvasive carcinoma work?
- carcinoma in situ cells convert to mesenchymal cells
- expression of cadherin is reduced
- invasion is aided by protrusions called invadipodia
- secretion of metalloproteases
- bm breached