Calcium signaling Flashcards
1
Q
Why are calcium signals far more rapid than that of other signals?
A
The high gradient difference between outside the cell and inside
2
Q
What are sources/sinks of calcium?
A
- endoplasmi/sarcoplasmic reticulum
- nuclear envelope
- mitochondria
3
Q
How is calcium moved from the cytoplasm through the plasma membrane?
A
- voltage and ligand-gated Ca2+ channels
- store operated Ca2+ channels (Orai 1)
- Ca2+ moves from outside cell into plasma
4
Q
How is calcium moved from the ER/SR and nuclear envelope to the cytoplasm?
A
IP3 receptors and ryanodine receptors -> Ca2+ moves downhill from lumen of ER/SR to cytoplasm
5
Q
How is calcium moved from the mitochondria to the cytoplasm?
A
- mitochondrial uniporter and permeability transition pore
- direction depends on Ca2+ gradient
6
Q
How are store-operated Ca2+ channels activated?
A
by depletion of Ca2+ from ER/SR
7
Q
How is Ca2+ moved into extracellular space or into lumen of ER/SR?
A
Ca2+ pumps using ATP
8
Q
How is Ca2+ moved across the plasma membrane?
A
Na+/Ca2+ exchangers (3Na for 1Ca2+)
