title: Spatial organization of intracellular Ca2+ signals.
abstract: The ability of Ca(2+), the simplest of all intracellular messengers, selectively to regulate so many cellular behaviours is due largely to the complex spatiotemporal organization of intracellular Ca(2+) signals. Most signalling pathways, including those that culminate in Ca(2+) signals, comprise sequences of protein-protein interactions linked by diffusible messengers. Using specific examples to illustrate key principles, we consider the roles of both components in defining the spatial organization of Ca(2+) signals. We discuss evidence that regulation of most Ca(2+) channels by Ca(2+) contributes to controlling the duration of Ca(2+) signals, to signal integration and, via Ca(2+)-induced Ca(2+) release, to defining the spatial spread of Ca(2+) signals. We distinguish two types of protein-protein interaction: scaffolds that allow rapid local transfer of diffusible messengers between signalling proteins, and interactions that directly transfer information between signalling proteins. Store-operated Ca(2+) entry provides a ubiquitous example of the latter, and it serves also to illustrate how Ca(2+) signals can be organized at different levels of spatial organization - from interactions between proteins to interactions between organelles.
authors.affiliation: Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, UK.
authors.forename: Vera
authors.initials: V
authors.lastname: Konieczny
authors.forename: Michael V
authors.initials: MV
authors.lastname: Keebler
authors.forename: Colin W
authors.initials: CW
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling; D002450:Cell Communication; D003600:Cytosol / Q000378:metabolism; D004058:Diffusion; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D009249:NADP / Q000031:analogs & derivatives / Q000378:metabolism; D011485:Protein Binding; D060066:Protein Interaction Maps; D021381:Protein Transport
chemical_list: D015220:Calcium Channels; D009249:NADP; C024376:NAADP; D002118:Calcium