Research in our laboratory is focused on the molecular and cellular mechanisms of intracellular calcium (Ca2+) signaling. Ca2+ is a ubiquitous intracellular signaling messenger, mediating many essential functions including gene expression, chemotaxis, and neurotransmitter release. Cellular Ca2+ signals generally arise from the opening of Ca2+ permeable ion channels, a diverse family of membrane proteins. We are studying Ca2+ signals arising from the opening of Store-Operated channels (SOCs), a family of plasma membrane Ca2+ channels activated by a decrease in the calcium content of the endoplasmic reticulum (ER). Human patients with mutations in SOCs suffer from devastating immunodeficiencies, muscle weakness, and a spectrum of defects in the brain, airways, and numerous other tissues, underscoring their vital importance for human health. We are studying the molecular and cellular mechanisms by which SOCs are activated and the mechanisms by which they regulate gene expression, effector cell responses, and brain function.