title: Fine tuning of cytosolic Ca (2+) oscillations.
abstract: Ca (2+) oscillations, a widespread mode of cell signaling, were reported in non-excitable cells for the first time more than 25 years ago. Their fundamental mechanism, based on the periodic Ca (2+) exchange between the endoplasmic reticulum and the cytoplasm, has been well characterized. However, how the kinetics of cytosolic Ca (2+) changes are related to the extent of a physiological response remains poorly understood. Here, we review data suggesting that the downstream targets of Ca (2+) are controlled not only by the frequency of Ca (2+) oscillations but also by the detailed characteristics of the oscillations, such as their duration, shape, or baseline level. Involvement of non-endoplasmic reticulum Ca (2+) stores, mainly mitochondria and the extracellular medium, participates in this fine tuning of Ca (2+) oscillations. The main characteristics of the Ca (2+) exchange fluxes with these compartments are also reviewed.
authors.affiliation: Unité de Chronobiologie Théorique, Faculté des Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Dupont
authors.affiliation: Interactions Cellulaires et Physiopathologie Hépatique, UMR-S 1174, Université Paris Sud, Orsay, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Combettes
keywords: calcium oscillations; mitochondrial Ca2+ uniporter; mitochondrial Ca2+ uptake 1; store-operated calcium entry