Flashcards in Epithelium: Apical Differentiations and CAM Deck (55):
a type of primary cilia that is part of the organ or corti in the inner ear
What lines the oviduct?
ciliated epithelial cells
Clijum is made up of..
microvilli are made up of
sterocillium are made up of
basal lamina is made up off
type 4 collagen +laminin
the reticular lamina is made up of
collagens, fibronectin, proteoglycans
Cadherins have how many calcium domains?
What sequence on the Cadherin facilitates cis-homophillic dimer formation
What are the three actin binding proteins on Cadherins?
Vinculin, formin-1, alpha actinin (catinins)
Name calcium dependent CAM?
Cadherin and Selectin
Name Calcium independent CAM?
IgSF and Integrins
E-cadherin is found in..
N-cadherin is found in...
CNS, lens of the eye, cardiac and skeletal muscle
P-Cadherin is found in...
Removal of Calcium disrupts...
What CAMS bind to F-Actin?
Cadherins and Integrins
What are the actin binding proteins for integrins?
Vinculin, talin, alpha actinin
beta catinin is also seen as a
transcriptional cofactor....colorectal carcingenisis
What are the three distinct apical differentiations?
Carbohydrate recognizing domain
What alters the carbohydrate recognizing domain in Selectins?
Calcium bound at the sides of the CRD regulates the conformation of the domain and its ability to bind carbohydrates
What CAMs play a part in homing?
Integrins attached to ICAM
Selectins mediate interactions between what...
leukocytes and endothelial cells or blood platlets
(intiate interactions between leukoctes from circulation to the sites of tissue inflammation)
Activated endothelial cells (blood vessels)
platelets and activated endothelial cells lining blood vessels (stored inc ytoplasmic vesicles in endothelial cells)
**on surface leukocytes have sialyl lewis-x antigen(olgiosaccride ligand for P-selectin)
slow down leukocytes
Homing (describe process)
1. Selectins mediate initial adhesion of leukocytes to endothelial cells
2. formation of more stable adhesions in which integrins (on surface of leukoytes) bind to intracellular adhesion molecules (ICAMS, IgSF)
3. The firmly attached leukocytes penetrate hte walls of cpaillaries and enter the tissue by migrating between endothelial cells (transcellular pathway) Transendothelial migration
What are the main adhesion proteins holding peithelial cells together?
Which part of the Cadherin interacts wiht F-actin
The cytoplasmic Tail
What catinin directly binds to Cadherin
What catinin directly binds to actin
Selectins have how many extra cellular domains?
What are the three main domains of Selectins?
1. Carbohydrate recognition domain (olgiosaccrides when attached to protien glycoprotein.. when attached to lipid glycolipid)
2. Epidermal Growth Factor like domain
3. Consenus repeats
IgSf (immunoglobulin superfamily)
extracellular domain adhesion molecule
trans heterophillic/homphillic bidning
Different types of IgSf
NCAM-neural tissues/nerve cells
ICAM-btwn leukocytes and endothelial cells (integrins on the surface of leukocytes bind to ICAMS) more stable adhesion
CAMS Important in T cell interactions and binding of leukocytes to activated or resting endothelial cells
Encoded by a single gene
What is the receptor for HIV-1 (tcells/helper cells)
heterodimers (alpha and beta subunits)
Do Integrins have cytoplasmic or extracellular Domain?
What links integrins to actin?
Connecting Protiens (Vinculin, Talin, alpha actinin)
What sequence do integrins recognize?
RGD sequence found in fibronectinin and laminin
What subunit recognizes the RGD sequence?
the beta subunit
What regulates the beta subunit binding in integrins?
the alpha subunit
What links the cytoskeleton to the ECM?
Laminin is found where?
in basal lamina
made by epithelial cells
Fibronectin is found where?
in recticular lamina
made by fibroblast
In hemidesmosomes integrins link...
basal lamina to intermediate filaments
**which link the basal domain to the basement membrane**
Steps of Homing
1. rolling: L-selectin
2. adhesion: integrin activation (trigged by inflamm substances...chemokines)
3. Transendothelial migration (diapedesis) involves f actin and myosin
Purpose of Homing
to help with the moment of leukocytes from the blood stream to their home ( lymph nodes and thymus) or connective tissue
( A Disintegrin A metalloprotease)
reversal of integrin mediated cell binding to ECM disrupted by
needs zinc for proteolytic activity