CellSig8 - 10 Flashcards Preview

Y2S2 - Cell Signalling > CellSig8 - 10 > Flashcards

Flashcards in CellSig8 - 10 Deck (10):
1

What is the Ca wave in the egg caused by?

Phospholipase C in the sperm

2

What is special about Ca as a signalling molecule?

Never created or destroyed - only its concentration is controlled

3

How is cytosolic Ca kept low?

Na-driven Ca exchanger (nerves/muscles), PMCA (PM Ca ATPase), SERCA (SER Ca ATPase), Ca uniporter (mitochondrion)

4

Characterise SERCA1-3

1+2 in types of muscle, 3 in non-muscle cells

5

What is thapsigargin?

Selectively inihibits SERCA activity

6

How is cytosolic Ca increased?

Voltage dependent Ca channels in PM, IP3-gated allow escape from ER, ryanodine receptors release Ca from sarcoplasmic reticulum

7

What inhibits the IP3 Ca release pathway?

Ethanol and caffeine - relaxants

8

Why is calmodulin very important?

1% of cell protein, activates MLCK, allows myosin head to interact and thus facilitates contraction of muscle

9

Outline MLCK cycle

Inactive + Ca-calmodulin > activated + auto-phosphrylation > fully active > Ca independent > dephosphorylation > inactive

10

How is MLCK involved in memory?

Activation = memory of prior Ca pulse. Used in vertebrate nervous system