The primary effectors of Gβγ are various ion channels , such as G protein-coupled inwardly-rectifying potassium channel ( GIRKs ) , P-type calcium channel / Q-type calcium channel - and N- type voltage-gated Casup2 + / sup channels , as well as some isoforms of AC and PLC , along with some phosphoinositide-3-kinase ( PI3K ) isoforms .