Cell Adhesion Flashcards
what is cell adhesion
What would happen if there was no cell adhesion and why is cell adhesion needed
Needed for cell recognition and tissue formation
Also needed for cell organisation, resistance and strength, barrier formation, communication with surrounding cells and the ECM
What effects can cell adhesion have on a cell
What is cell adhesion involved in
How is cell adhesion involved in multicellularity
What are the 4 different types of adhesion structures
What is the basic structure of the epithelia
Label the different parts of this cell junction in epithelia
What are homophilic interactions and why are they useful
one type of adhesion molecule will only adhere to the same type of adhesion molecule
E.g cadherins on one cell interact with cadherins on another cell
Useful as it helps cells of the same type to stick together which helps form tissue
What are heterophillic interactions
One type of adhesion molecule will interact with a different type of adhesion molecule
What are the characteristics of desmosomes
are specialized cell structures that function primarily to provide strong adhesion between cells in tissues that experience considerable mechanical stress, such as the skin, heart, and certain epithelial tissues
Uses desmosomal cadherins for adhesion
Attached to intermediate filaments
Used for strength, durability and signalling
What are the characteristics of adherens junctions
Cell to cell adhesion
Cadherins used for adhesion
Attatched to actin filaments
Used for shape, tension and signalling
What are the characteristics of hemidesmosomes
Adhesion between cell and ECM
Integrin used for adhesion
Attached to intermediate filaments
Used for shape, rigidity and signalling
What is the structure of an adheren junction
What is the structure of desmosomes
Which cell adhesion molecules undergo homophillic interactions
Cadherins (E-cadherins)
CAMs (cell adhesion molecules)
Which cell adhesion molecules undergo heterophillic interactions
Integrins
Selectins
What is the structure of a classical cadherin polypeptide
Blue= cadherin domain
How do cadherins on one cell bind to cadherins on another cell
What is the function of calcium in cadherins
What are the 4 types of classical cadherins q
Where are the main location of the classical cadherins
What happens if the 4 types of cadherins are inactivated in mice (E, N, P and VE respectively)
What is a characteristic of cell adhesion
It’s dynamic
Adhesion protein gene expression changes over time and adhesions assemble and disassemble
At is an adherin junction
How do adherens work and what do they do
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What is the function of adherens
What can changes in cell adhesion do
What is integrin and how does its structure relate to its function
How does integrin interact with the cell and the ECM
Give some examples of integrins and the ligand it binds to
What is the phenotype when the alpha subunit of each type of integrin is mutated, respective to this order:
What is the phenotype when the beta subunit of each type of integrin is mutated, respective to this order:
How can integrin be activated
Integrin can be activated from two directions, from the inside by the regulated binding of proteins to the cytoplasmic tails, and from the outside by multivalent ligand binding
What happens when an extra cellular ligand binds to integrin
Label the different parts of integrin on this diagram
How can integrin be activated ‘inside-out’ (activated from the inside)
What are igCAMS
What is the function of Ig-CAMS
What is the structure of Ig-CAMS
Orange = type III fibronectin repeat
Green= Ig domain
What is the structure of integrins
Blue= cadherin domain
Red= lectin domain
Orange= type III fibronectin repeat
What is the structure of selectins
Red= lectin domain
Orange= type III fibronectin repeat
What is the function of selectins
What are transient interactions
involve protein interactions that are formed and broken easily
What is blood rolling
Leukocyte rolling describes the low affinity adhesive interaction between leukocytes and the vascular endothelium whereby the force of blood flow induces a rotational motion (i.e., rolling) of the leukocyte along the vascular wall.
How are selectins involved in blood rolling
selectins mediate leukocyte capture and rolling along the vessel wall whereas interactions between integrins and Ig superfamily members arrest rolling cells and mediate firm adhesion
