Cell Junctions And Adhesions Flashcards
Tight Junctions
Encircle entire cell like a belt
Actively regulate permeability of small molecules
Mutation in Claudine lead to
Kidney calcification
Deficient Ca and K reuptake
Belt desmosomes
Encircle entire cell, right below tight junctions
Tight junctions are linked to _______ cytoskeleton by _______
Actin
Adaptor proteins
Belt desmosomes connected to _______ cytoskeleton by ______
Actin
Catenins
E Cadherin
Present in belt desmosomes
Important for cell-cell adhesion
P cadherin
In belt desmosomes Selectively distributed (retina, hair follicles)
Spot desmosomes
Spot like cell-cell junctions
Spot desmosomes are linked to _______ Cytoskeleton by _______
Intermediate filaments
Adaptors (desmoplakin, plakoglobin, plakophilin)
Integrins interact with ________ on __________-
ECM proteins
RGD sequence
Integrins
Present in actin-linked cell-matrix adhesion sites (focal adhesions) Transmembrane protein (alpha/beta subunit)
Hemidesmosome
Interaction between cells and basement membrane
Mechanical strength
Cell anchorage
Focal adhesions
Important for cell migration
Gap junctions
Coordinate cellular responses
Connexon channels
Allow small molecules to pass cell-cell
Permeability is regulated
Formed by 6 connexin proteins
Selections
Transmembrane proteins that are Ca dependent
Bind oligosaccharides
Role in inflammation
Immunoglobulin superfamily
Do NOT need Ca
It-like domain on extracellular side
Connexin 26 mutation
Leads to deafness
In cochlear hair cells
Connexin 32 mutation
Leads to peripheral neuropathy
In myelin
Steps to Leukocyte Extravasation (4)
- Leuk. Slows down and starts rolling due to loose adhesion with selectins on surface
- Integrins activated on leuk. That bind to ICAM/VCAM on endothelial cells
- Leuk. Stops bc strong adhesive forces
- Integrin-mediated migration btwn endothelial cells (through blood vessel wall)
