The organisation and functions of local Ca2+ signals

Calcium (Ca2+) is a ubiquitous intracellular messenger, controlling a diver se range of cellular processes, such as gene transcription, muscle contract ion and cell proliferation. The ability of a simple ion such as Ca2+ to pla y a pivotal role in cell biology results from the facility that cells have to shape Ca2+ signals in space, time and amplitude. To generate and interpr et the variety of observed Ca2+ signals, different cell types employ compon ents selected from a Ca2+ signalling 'toolkit', which comprises an array of homeostatic and sensory mechanisms, By mixing and matching components from the toolkit, cells can obtain Ca2+ signals that suit their physiology. Rec ent studies have demonstrated the importance of local Ca2+ signals in defin ing the specificity of the interaction of Ca2+ with its targets. Furthermor e, local Ca2+ signals are the triggers and building blocks for larger globa l signals that propagate throughout cells.