Functional organization of PLC signaling microdomains in neurons

Our understanding of receptor transduction systems has grown impressively in recent years as a result of intense efforts to characterize signaling molecules and cascades in neurons. A large body of evidence has recently accrued regarding the fast and effective signal transfer that occurs during phosphoinositide signaling. In particular, dissection of the Drosophila phototransduction pathway has enabled a greater understanding of the molecular organization of phospholipase C (PLC) signaling. Supramolecular complexes organize the correct repertoires of receptors, enzymes and ion channels into individual signaling pathways. Such mechanisms involve localization of signaling molecules to sites of action by scaffold and anchoring proteins, ensuring speed and specificity of signal transduction events. However, not all PLC signals nucleate around scaffold proteins, although mechanisms for selectivity and discrimination remain. This article reviews recent advances on the molecular organization and functional consequences of PLC signaling domains, which link membrane receptors to ion channels, including TRIP and KCNQ channels.