CHAPTER 26: Intracellular Calcium Modulation of Gene Expression

Cells have developed a variety of mechanisms to keep free calcium ion concentrations at very low levels in the cytosol. These mechanisms allow transient increases in cell calcium concentrations to be used as signals to trigger a variety of cellular processes, gene expression being one of them. Skeletal muscle relies on nerve activity both for contraction and also for the expression of genes related to pathways that include survival and the plastic changes required for adaptation to exercise. A particular pathway that involves Cav1.1 as a voltage sensor for nerve activity, pannexin-1 channels to release ATP to the extracellular milieu, purinergic P2Y receptors to link the signal via G protein to PI3 kinase and phospholipase C, will finally give rise to slow, long-lasting calcium transients in the nuclear region that can be linked to either expression or repression of a variety of genes. This mechanism appears to be the basis of fast to slow muscle fiber transition.