Calcium Signaling

Question 1

Function of Cytoplasmic Calcium Buffers

Answer 1

Bind Ca and effectively restrict spatial and temporal spread of calcium in cytoplasm. Allows for fast signaling due to fast influx without saturating all of cytoplasm with calcium. Creates specific and diverse calcium signaling based on location of influx.

Question 2

Routes of Calcium entering cytoplasm (7)

Answer 2

Voltage gated channels in PM
Ligand gated channels in PM (nACh, Glutamate)
Store-operated channels in PM, Orai1 (Stim1)
RyR in ER/SR
IP3 Rs in ER/SR (PLC)
Uniporter in mito (Na:Ca exchange)
mPTP

Question 3

Removal of Ca into extracellular (2)

Answer 3

PMCa ATPase pumps

3:1 Na:Ca exchanger (also mito)

Question 4

Removal of Ca into ER/SR (1)

Answer 4

SERCa ATPase pumps

Question 5

EF Hands

Answer 5

Calcium biding sites coordinated with 5 oxygen molecules (associated with backbone, aspartate, gluatamate). Found in many effectors and is used to confer calcium regulation on other proteins (Calmodulin, Parvalbumin, Troponin)

Question 6

C2 domains

Answer 6

protein motifs that target protein to membrane after Ca binding.