Calcium Signaling IICalcium and Disease

Calcium (Ca2+) plays a major role in controlling cell function. It regulates life and death processes that include fertilization, cell proliferation, apoptosis and cell necrosis. It controls functional responses including muscle contraction, cell migration, secretion, metabolic pathways, gene expression and cell differentiation. The basic element of Ca2+ signalling is to... read morekeep the cytoplasmic calcium ([Ca2+]c) low and then allow selective increases in [Ca2+]c by stimulating either Ca2+ release from the cells’ internal Ca2+ stores or the influx of Ca2+ from the extracellular environment. Inside the cell, elevated Ca2+ will activate regulatory proteins (many of its actions are mediated through Ca2+-binding proteins such as calmodulin) or enter intracellular organelles where it can regulate their internal processes. Ca2+ signals are attenuated by sequestration of Ca2+ into intracellular organelles that function as Ca2+ stores or by the expulsion of Ca2+ back across the plasma membrane.

Since Ca2+ regulates so many diverse processes including cell fate, it is not surprising to find altered Ca2+ homeostasis linked with disease. This linkage can arise through mutations in proteins that regulate Ca2+ homeostasis, altered expression of Ca2+ regulatory proteins or over stimulation and activation of pathways leading to Ca2+ overload in the cell. Whilst Ca2+ overload may lead to cell death, disruptions of Ca2+ homeostasis that are not fatal can lead to changes in cell function that have pathological consequences.

Ca2+ signalling is an extremely active research field. Series I is designed to cover the key processes that contribute to cellular Ca2+ homeostasis and includes topical issues and recent developments described by the fields’ leading scientists. Series II focuses on the rapidly expanding topic of Ca2+ and disease. It is designed to give an insight into the broad range of pathologies that involve a disturbance of Ca2+ signaling.