CTCS Quiz 4: Signaling Flashcards
On PI3K, what region inhibits what region?
p85 inhibits p110
What important molecule does PI3K mediate?
insulin
What does PIP3 do?
Glucose uptake and metabolism
What does PI3K do?
It gets glucose into the cells.
Why is intracellular Ca++ so low?
It loves to precipitate with phosphate, and there is a shit ton of phosphate in the cell.
Why is Ca++ a good signal?
- low levels, so a little increase makes a lot of noise.
- many sensors.
- Converts signals from electric to chemical.
What are some great ways to get rigs of Ca++?
Diffusion
Extrusion via pumps and exchangers
Sequestration in organelles
Cytoplasmic buffers
What are 4 examples of Ca++ signaling?
- Synaptic Transmission
- Muscle Contraction
- T Cell Activation
- Mitochondria and Death
What is the most ubiquitous Ca++ receptor?
Calmodulin.
Why does the ER strangle the Mito? What is the effect?
To get Ca in. Increasing Ca++ can rev up metabolism, or too much makes the Mito leaky which leads to apoptosis.
What are the 6 domains of NRs?
1/2. N-terminal
- DNA binding domain (DBD)
- Hinge Region
- Ligand Binding Domain
- C-terminal Domain
Do most of the NR superfamily dimerize?
Yes.
How does the H12 region of the binding domain change conformation?
No Ligand: Sticking out in space, interacts with co-repressors.
Ligand: folds in to allow binding to co-activators.
How do steroid hormones get to the nucleus?
Connected to albumin in blood > connect to NR (which are attached to HSP90) in cytoplasm > NR is released from HSP90 and they dimerize in the cytoplasm > enter nucleus and NR bind to DNA initiating transcription.
What are the 4 steps of neurulation?
- Forming neural plate
- shaping the neural plate (narrow and lengthen)
- bending the neural plate
- closing neural grove in the dorsal midline to form the neural tube
