Figure 2. Diagram of the relevant PIP₂ pathways.

Upon stimulation of G_q‐coupled receptors, the α component of the G‐protein activates phospholipase‐C (PLC), which cleaves membrane‐bound PIP₂ into diacylglycerol (DAG) and inositol trisphosphate (IP₃). DAG activates protein kinase C while IP₃ triggers release of Ca²⁺ ions from internal Ca²⁺ stores. U73122 blocks the activity of PLC. PIP₂ has been demonstrated to modulate several ion channels in previous studies, such as Kv7 channels (Suh & Hille, 2007) and SK channels (Zhang et al. 2014). Inset, the dashed box displays the pathway for production of different PIP molecules (blue hexagons), and the enzymes that phosphorylate each of them (purple boxes). Wortmannin blocks synthesis of PIP₂ and PIP₃ production while LY294,002 only blocks PIP₃ production. Both work by blocking the synthetic enzymes.