what are the 4 groups of cell adhesion molecules (that we need to know)?
bind the CYTOSKELETON to ECM at FOCAL ADHESIONS in cultured cells
CAM TYPE #1: INTEGRINS what do integrins do?
- tissue integrity - organization
CAM TYPE #1: INTEGRINS interactions of cells with ECM (and therefore integrins) is key to tissue ___ and ____
dimer (alpha-beta subunits)
CAM TYPE #1: INTEGRINS what are integrins (structurally)?
via RGD sequence (Arg-Gly-Asp acid)
CAM TYPE #1: INTEGRINS how do integrins bind to ECM proteins?
no (through protein)
CAM TYPE #1: INTEGRINS
TRUE OR FALSE integrin binds actin directly
calcium-dependent adhesion molecules
CAM TYPE #2: CADHERINS what are cadherins (structurally)?
mediate homotypic cell-cell adhesion in the presence of calcium
CAM TYPE #2: CADHERINS what do cadherins do?
- in a variety of tissues - at the ZONULA ADHERENS = BELT DESMOSOMES in intestinal epithelial cells
CAM TYPE #2: CADHERINS where are cadherins found?
CAM TYPE #2: CADHERINS interaction with SPECTRIN- and ANKYIN-LIKE proteins (the ____) associated with ACTIN filaments at adherent junctions (BELT DESMOSOMES)
because EC segments of CAMs fold into 2-6 Ig-like domains
CAM TYPE #3: IG SUPERFAMILY why are Ig-superfamily of proteins named as such?
- TCRs - IGs - MCH I and MCH II - CD4 and CD8 (in picture?) - NCAMs (in picture?)
CAM TYPE #3: IG SUPERFAMILY what are some example of Ig superfamily CAMs?
(is that what this slide is saying?)
CAM TYPE #3: IG SUPERFAMILY Ig superfamily molecules on one cell can bind to ____ molecules on another cell
what is this called?
ICAM and VCAM
CAM TYPE #3: IG SUPERFAMILY what 2 molecules play an important role in T-CELL interactions and binding of LEUKOCYTES to activated or resting ENDOTHELIAL cells?
- a CHO recognition domain (CRD) specific for a particular SUGAR
- domain homologous to a repeat found in EGF
- many consensus repeats found in complement regulatory proteins
CAM TYPE #4: SELECTINS selectins have 3 domains. what are they?
- L selectins - E selectins - P selectins
CAM TYPE #4: SELECTINS what are the 3 major types of selectins?
- carried by lymphocytes - bind to SULFATED CHOs
CAM TYPE #4: SELECTINS who carries L selectins? what do they have a binding affinity for?
activated endothelial cells
CAM TYPE #4: SELECTINS who expresses E selectins?
platelets and activated endothelial cells
CAM TYPE #4: SELECTINS who expresses P selectins?
- integrins - ICAMs
CAM TYPE #4: SELECTINS selectins, together with ___ and ____ molecules, play a significant role in INFlAMMATION and in the periodic MIGRATION OF LYMPHOCYTES from the circulation into lymphoid organs. What is this called?
- selectin phase - integrin phase
what are the 2 phases of honing?
1) neutrophils resist shear forces to slow down
2) selectins on endothelial bind to CHO on neutrophil
3) integrin receptors for ICAM1 and ICAM2 are activated, strengthening bond
4) transendothelial migration
what are the steps of honing?
- shear forces - rolling
which steps of honing take place during the selectin phase?
- strengthening of leukocyte-endothelial cell bond - transendothelial migration
which steps of homin take place during the integrin phase?
High Endothelial Venules (HEVs)
what allows for the transition of lymphocytes from the blood stream to the lymph tissues?
- deep cortex - medulla of lymph nodes
where are HEVs located?
lymphocyte (L) is squeezing its way through the junctino of 2 endothelial cells