Lecture 06 Flashcards
What type of junction is more prominent in epithelial tissues?
Cell-cell junctions
In what type of animal tissues is cell-matrix junctions more prominent?
Connective tissues (i.e. blood, adipose, dense, loose, cartilage)
What are the 6 various junctions of cells?
- Tight junction
- Adherens junction
- Desmosome
- Gap junction
- Hemidesmosome
- Actin-linked cell-matrix junction
Adherens junction, desmosome, hemidesmosome,
and actin-linked cell-matrix junction are also called the _______________.
Anchoring junctions
T or F. The anchoring junctions plus the gap junction make up the junctional complex.
False. The anchoring junctions plus the TIGHT junction make up the junctional complex. The gap junction is excluded from the junctional complex.
Seals the gap between cells to prevent molecules from leaking across the epithelium
Tight junction
Group the 4 anchoring junctions in terms of (transmembrane) adhesion proteins.
- Cadherins - adherens junction & desmosome
- Integrins - actin-linked cell-matrix junction & hemidesmosome
Group the 4 anchoring junctions in terms of cytoskeletal component.
- Actin - adherens junction & actin-linked cell-matrix junction
- Intermediate filament - desmosome & hemidesmosome
Word(s) association. Junction made up of:
Actin; Cadherins
Adherens junction
Word(s) association. Junction made up of:
Nonclassical cadherins; Actin
DOES NOT EXIST
Word(s) association. Junction made up of:
Intermediate filament; Integrins
Hemidesmosome
Word(s) association. Junction made up of:
Cadherins; Intermediate filament
Desmosome
Word(s) association. Junction made up of:
Actin; Integrins
Actin-linked cell-matrix junction
T or F. The cadherins of bacteria are always connected to actin filaments.
False. Bacteria has NO cadherins
Where do cadherins take their name from?
Their dependence to Ca2+
Which type of cells do NOT have cadherins?
a. epithelial
b. nerve
c. placenta
d. lens
e. none of the above
E. All these cells have cadherins.
T or F. Integrins mediate homophilic adhesion.
False.
Cadherins - homophilic.
Integrins - heterophilic.
Mechanotransduction is present in which junction?
Adherens junction
Helps prevent apical or basolateral transport proteins from diffusing into the other region.
Tight junctions
Movement of ions and other molecules between epithelial cells
Paracellular transport
Two main tight junction proteins
Claudin and occludin
Claudin functions for _____________ while occludin governs ______________.
assembly of the sealing strands; junction permeability
Mnemonic: CLaudin CLoses. Occludin Opens
Large scaffold proteins providing structural support on which tight junction is built.
ZO (zonula occludens)
