LAUSR

Phospholipase C-β (PLCβ) is activated by G protein signals from different hormones and neurotransmitters on the plasma membrane, to mediate increases in intracellular calcium. Surprisingly, we find that PLCβ also localizes to the cytoplasm where it plays an important role in RNA-induced gene silencing by interacting with the component 3 promoter of the RNA-induced silencing complex (C3PO) as well as one of the key components of the RNA-induced silencing machinery, Argonaute 2 (Ago2). We also find that PLCβ distributes between its two binding partners, Gαq and C3PO/Ago2, to promote calcium signaling or RNA-induced silencing. For example, Using bimolecular fluorescence complementation, FLIM and FCS we find that the interaction of PLCβ with Ago2 and C3PO change with neuronal differentiation. We propose that the ability of PLCβ to shuttle between its two binding partners to carry out these two different functions plays a key role in the normal physiological processes of cells.