LECTURE 16 – March 8th
Anchoring junctions continued….
SELECTINS – the next type of anchoring junctions
Type of lectin
Lectins are carbohydrate-binding domains”
To oligosaccharides on other cells”
Not catenins in this case – don’t need to know the actual name
Also clustered – giving interaction high avidity – strong Velcro interaction
Blood vessel
Cells secrete yellow stuff, which cells stick to
Epithelium lined blood vessel = endothelium
Rolling on cells – because of infection
oSecreting signal received by endothelial cells in nearby blood vessel, which
begin to express p-selectin which is now sticking out of membrane, and
start to attract or stick to the cells,
Rolling is selectin-dependent
Sticking mechanism based on integrins
Weak adhesion and rolling on selectins – strong adhesion and
integrins
Cells will move in between endothelial cells and
Extravization ?
DRAW TABLE to summarize
Other anchoring junctions
Immunoglobulin superfamily
oThese proteins have immunoglobulin domain
oImmunoglobulin = antibody
oAntibody made up of those Ig domains
oCD4 = ex. of immunoglobulin superfamily protein
oMultiple Ig-like extracellular domains”
oMediate calcium-independent, homophilic or heterophilic receptor
interactions”
DESMOSOMES
Like adherence junction
Like cadherin like proteins outside cell but inside cell, linked to intermediate
filaments, instead of actin
Bind intermediate filaments”
Adaptor proteins linking adhesion complex to intermediate filaments – not
catenins, different proteins
Strengthening tissues”
www.notesolution.com