8 Flashcards
What is a migrasome?
A migrasome is a specialized vesicle that forms when a cell undergoes migration, particularly during processes like wound healing or tissue development.
What is the phenotype when GSK-3 is KO?
GSK-3 in the Wnt pathway is responsible for the degradation of β-catenin in the absence of Wnt signals.
A KO would cause b-cat to be constitutively active = cancer
what is ZO-1?
ZO-1 is a tight junction protein involved in regulating cell-cell adhesion and permeability.
What is Plecstrin and it’s a substrate of?
pleckstrin is a signaling protein that regulates actin dynamics and plays a role in immune and platelet cell functions, with its main substrate being PIP2.
mutations in the Wnt/Wg pathway? (Bad hair)
- Dish
- B-cat (armadillo)
- Frizzled
- GSK-3 (Shaggy)
what does Alizarian Red stain?
Bone
What does Alcian blue stain?
Cartilage
what is key to canonical wnt signalling?
B-catenin
what is required in ALL Wnt signalling?
The scaffolding protein Dishevelled is required in all Wnt signaling
Canonical Wnt is usually related to what?
transcriptional events
What are stereocilia?
They are involved in mechanotransduction, where they convert sound or motion into electrical signals.
What is a kinocilium?
A kinocilium is a non-motile cilium found alongside stereocilia in some sensory cells.
It plays a role in the orientation and proper functioning of stereocilia, particularly in the inner ear’s balance system.
What are ankyrin repeats?
Ankyrin repeats help mediate signal transduction, cytoskeletal organization, and cellular adhesion
what do Vangal and Prickle do?
negatively regulate Wnt
what do Dgo and Dsh do?
-Dgo binds Dsh & helps tether Fmi to PM
what is Flamingo (Fmi) ?
Fmi is a GPCR/cadherin
what protein has Ankyrin repeats?
-Diego (Dgo, “Inversin”) has ankyrin repeats
Steps in Establishing Planar Cell Polarity (PCP) in Flies
Flamingo (Fmi, Stan) localizes at cell junctions and interacts with adjacent cells.
Diego (Dgo) binds Dishevelled (Dsh) and helps tether Fmi to the plasma membrane (PM).
Vangl and Prickle (Pk) negatively regulate Wnt signaling and oppose Dsh-Dgo-Fmi.
Fz-Dsh-Dgo-Fmi on one side (distal).
Vangl-Pk-Fmi on the opposite side (proximal).
Cytoskeletal reorganization aligns cellular structures (e.g., wing hairs, stereocilia).
Steps in PCP Establishing Polarity
Dishevelled (Dsh) is activated and recruits DAAM
DAAM activates Rho and Rac GTPases
RhoA activates ROCK (Rho Kinase), leading to actin cytoskeleton reorganization and cellular alignment.
Rac activates JNK which activates c-Jun, influencing gene expression.
Regulates actin cytoskeleton dynamics, reinforcing polarity.
Coordinated cytoskeletal changes establish and maintain planar cell polarity across tissues.
Rho is inactive by —- …how?
Rho is inactive by Guanine Nucleotide Dissociation Inhibitors (GDI’s)
they inhibit them from getting to the PM
How is Rho activated and by what?
Rho is activated by GTP and embedded in PM
** GEFs recruit the GTP to the Rho
What does a cell produce to digest the ECM?
MMPs
“RECAP” Rho, Rac (and CDC42) characteristics
-bind GDP/GTP
-present as GDP-bound proteins in cytosol, linked to GDI’s
-guanine nucleotide exchange factor (GEF) activates them
-Activation affects many things (cytoskeleton)
-GAPs shut off the signal, and GDIs keeps them off!
What is difference between migration and invasion?
Migration is the movement of cells from one location to another
invasion involves migration plus the ability to degrade or move through extracellular matrix barriers.
Boyden Chamber Purpose?
The Boyden chamber is used to study cell migration and invasion
there is a chemoattractant placed at the bottom of a chamber to which invasive cells must break down a barrier (ECM-like) to get to
