Cell Junctions Flashcards
Define: cadherins
Calcium dependent adhesion
What are the 4 different kinds of cell junction proteins?
- Cadherins
- Integrins
- Ig-superfamily
- Selections
Are all the links between cells permanent?
No
Which are the 4 cell-to-cell junction types?
- Tight junction
- Belt desmosome
- Spot desmosome
- Gap junction
Which desmosome is connects the cell to the ECM?
Hemidesmosome
What is the main goal of a desmosome?
To give a cell strength
The three types of desmosomes are:
Spot, belt and hemi
What are the proteins of a spot desmosome?
Cadherins: desmoglein and desmocolin
Plakin proteins: plakoglobin and desmoplakin
Tonifilaments: keratin
What do the keratin filaments of the spot desmosome do?
Connect spot desmosome to spot desmosome
What is the cell junction?
An intercellular bridge with integral proteins that often link to cytoskeletal proteins
Which cadherins in the spot desmosome junction keep the desmosome together?
Desmocolin and desmoglein
What do hemidesmosomes do?
They link the cell to the ECM
What is the purpose of the plakin proteins?
help distribute stress
Which proteins allow the integral proteins to stay in place?
Desmoglobin and plakoglobin
The hemidesmosomes link ____ to _____
cell to ECM
Hemidesmosomes are closely related to _____
integrins
Hemidesmosomes use ____ and _____
integrins and plakin protein
The hemidesmosome link fibers through the ________ then the ______ and then ______ to the ______
plasma membrane then integrin then plakin protein and to the tonofilaments
Define: disintegrins
enzymes that breakdown integrins found in venom
Which desmosome is linked to actin?
belt desmosome
Belt desmosome give the cell the ability to ____ and gives _______
move; lateral stability
Belt desmosomes link the ___________
periphery of one cell to the periphery of another
A connexon is…
6 connexins
A gap junction causes a
1.5 nm channel where water and protons and calcium can move through
Gap junctions can…
open and close by twisting
DEFINE: OCCLUDING JUNCTION
it prevents movements through the ECM allowing the cells to have a top and bottom
The tight junction ____ the ECM
closes
Define: tight junction
the tight junction allows the things in tissue to stay in
Can large molecules move through plant cells?
Yes
