G-Protein Effectors

What does Gas do?

Stimulates AC (adenylyl cyclase); ATP → cAMP

What does Gai / Gao do?

Inhibit AC

What does Gaq do?

Stimulates phospholipase C (PLC) which causes Ca2+ to increase inside of the cell

What does Ga12 / Ga13 do?

Stimulates RhoGEF → Rho A (small G-proteins)

What does Gβγ do?

Decreases the activation/activity of voltage-gated Ca2+ channels

What happens if you activate Gao and Gβγ combinations together?

It decreases the opening of Ca2+ channels

What happens if you activate Gaz and/or some other Gβγ combinations?

It increases the opening of GIRK (G-protein-gated inwardly-rectifying potassium/K+) channels. (calms cells down)

What happens if you activate Gaq and/or some other Gβγ combinations?

Stimulates PLC (phospholipase C) and activate some downstream proteins and increase Ca2+ activity in the cytoplasm and PKC activity.

What happens when GPCRs bind with beta-arrestins?

3 effects: block G-protein signaling, couple GPCRs to clathrin (internalization/desensitization of GPCR), and activate signaling pathways.

What class is Tetracycline?

Aminoglycosides

What does Tetracycline do? Big or small?

Small subunit (30s); T-site. Blocks the A site.

What class is Azithromycin?

Macrolides

What does Azithromycin do? Big or small?

Big 50S subunit. Blocks the exit tunnel.