Studies shed new light on early transmembrane signaling

Two new studies by researchers at the University of Washington further our understanding of the molecular steps in the PLC cascade, a G protein-coupled receptor signaling mechanism that underlies a wide variety of cellular processes, including egg fertilization, hormone secretion, and the regulation of certain potassium channels. The studies appear online January 25 in the Journal of General Physiology.

Falkenburger et al. take advantage of recent progress in fluorescence technology -- which allows for analysis of biochemical events in single living cells—to perform a systematic analysis of the PLC signal transmission process.

According to Tamas Balla (National Institutes of Health) in a Commentary accompanying the articles, the new studies extend the kinetic model of the signaling cascade to cover the entire process, from the activation of the M1 muscarinic receptors to the regulation of the potassium channels. Specifically, Falkenburger et al. show the steps that link changes in PtdIns(4,5)P2 -- an important plasma membrane regulatory lipid—to changes in KCNQ potassium channel activity.