L24 Cell-Cell Junctions Flashcards
What are Adherens junctions?
They are protein complexes which play a crucial role on cell to cell adhesion and tissue organisation.
Name an adherent junction protein?
Cadherins.
What type of adhesion does cadherins do?
Ca2+ dependent adhesion.
What are the features of adherens junctions?
- Homophilic interaction.
- Makes strong links between cells.
- Links to actin cytoskeleton.
What are the actin linked junctions?
Adherens junction and focal adhesion.
What is the adhesion belt in morphogenesis?
Cadherin - Catenin - Actin - Myosin.
What does focal adhesion and adherens junction link to?
They link to the actin cytoskeleton.
What are desmosomes and hemidesmosomes?
They both are important cell junction which contributes to cell integrity and structure, where desmosomes form cell to cell junctions and hemidesmosome form cell to extracellular matrix junctions.
What are tight junctions?
They are specialized regions of contact between endothelial and epithelial cells forming a semi permeable barrier.
What is the role of tight junctions and where is it located?
Location - Epithelia
Roles
1.Prevent fluid, ion and membrane flow.
2.Variable extent
3.Transcellular transport
4.Paracellular transport
How is the sealing strands formed in tight junctions?
By ridges of transmembrane particles
Name and state the function of tight junction proteins?
Zonula occludens proteins bind claudin, occludin and actin
Define membrane compartments.
- Lipids And Proteins Segregated
- Apical Outer Membrane:
Glycolipid
Cholesterol - Basolateral:
Phosphatidylcholine
What is the length of gap junctions?
100 - 500 nm long
Where are the gap junctions distributed to?
Connective tissue, epithelia, neurons, heart muscle