Examples schematized are underlined. Abbreviations: POI = protein of interest. BD = binding domain, CIBN = cryptochrome interacting binding partner, CRY2 = cryptochrome, ER = endoplasmic reticulum, Gq* = activated Gαq, IP3 = inositol triphosphate, IP3R = IP3 receptor, LOV = light-oxygen-voltage, PLC = phospholipase C, Rec = membrane receptor.