Term
Functional Classification of Cell Junctions
(1) Occluding junctions – Tight junctions
(zonulae occludens)
(2) Anchoring junctions
(i) Adherens junctions (zonulae adherens)
(ii) Desmosomes
a) Desmosomes (maculae adherens)
b) Hemidesmosomes
(3) Communicating junctions – Gap junctions |
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Definition
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Term
| Tight unctions are composed of what two transmembrane glycoproteins? What Cytoskeletal protein? |
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Definition
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Term
(1) Diffusion barrier for paracellular transport (the ‘gate’ function)
(2) Maintain asymmetry (polarity) in protein and lipid composition between apical and basolateral cell surfaces
(the ‘fence’ function)
are the ??? |
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Definition
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Term
Blood-brain barrier is formed by joining endothelial cells of brain capillaries.
1. Prevents substances (unwanted solutes but also drugs) from passing from blood into brain tissues
2. Scientists want to figure out ways of temporary opening tight junctions to allow passage of big therapeutic agents |
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Definition
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Term
What Anchoring Junctions attach:
A. Cell-Cell: ???
B. Cell-Matrix: ??? |
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Definition
Adherens junctions & Desmosome
Hemidesmosome |
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Term
| Transmembrane linker glycoproteins are known as Cell Adhesion Molecules (CAM). Cadherins are CAM for what anchoring junction? Desmogleins & Desmocollins (desmosomal cadherins) are CAM for what anchoring junction? |
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Definition
Adherens Junction
Desmosomes |
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Term
Junctional Plaque Proteins
Vinculin & catenins (a & b)
–adherens junctions
Desmoplakins
-desmosomes |
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Definition
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Term
Cytoskeletal Proteins
1. Actin filaments
- adherens junctions
- tight junctions
2. Intermediate filaments (keratin)
- desmosomes
- hemidesmosomes |
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Definition
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Term
- Maintain cell-cell stability
- Involved in signal transduction
- Possibly involved in epithelial tube formation
are roles of? |
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Definition
| Role of Adherens junction |
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Term
| Maintain stability and strength between cells or between cell and extracellular matrix (ECM) |
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Definition
| Role of Desmosomes and Hemidesmosomes |
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Term
Communicating Junction:
Gap Junction
Connexin –gap junction protein (e.g., Cx26, Cx 43, Cx 46, Cx50)
Connexon –gap junction channel |
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Definition
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Term
Gap Junction
- 6 connexin subunits to form 1 connexon
- 2 connexons to form 1 cell-cell gap junction channel
Connexin family has many members (e.g., Cx26, Cx43, Cx46, Cx50) |
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Definition
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