Regulation of Ca2+ entry by inositol lipids in mammalian cells by multiple mechanisms.
Increased phosphoinositide turnover was first identified as an early signal transduction event initiated by cell surface receptors that were linked to calcium signaling. Subsequently, the generation of inositol 1,4,5-trisphosphate by phosphoinositide-specific phospholipase C enzymes was defined as the major link between inositide turnover and the cytosolic Ca(2+) rise in response to external stimulation. However, in the last decades, phosphoinositides have been emerging as major regulatory lipids involved in virtually every membrane-associated signaling process. Phosphoinositides regulate both the activity and the trafficking of almost all ion channels and transporters contributing to the maintenance of the ionic gradients that are essential for the proper functioning of all eukaryotic cells. Here we summarize the various means by which phosphoinositides affect ion channel functions with special emphasis on Ca(2+) signaling and outline the principles that govern the highly compartmentalized roles of these regulatory lipids.
Balla
Tamas
T
Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States. ballat@mail.nih.gov
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D054801:Phosphoinositide Phospholipase C / Q000378:metabolism; D015398:Signal Transduction
D007473:Ion Channels; D010716:Phosphatidylinositols; D015544:Inositol 1,4,5-Trisphosphate; D054801:Phosphoinositide Phospholipase C; D002118:Calcium