crac

CRAC is an acronym used in several domains, but it is most commonly associated with calcium release-activated calcium channels in biology. CRAC channels mediate calcium entry into cells when calcium stores in the endoplasmic reticulum are depleted. The channel is formed by Orai proteins and is regulated by STIM proteins, which sense store depletion and activate the channel at the plasma membrane.

In cellular signaling, CRAC channels drive store-operated calcium entry (SOCE), a fundamental pathway that supports diverse cellular processes. STIM1 and STIM2 act as ER calcium sensors, triggering Orai1/2/3 channels to open and allow calcium influx. This influx influences gene expression, secretion, muscle contraction, and the function of immune cells, among other roles. The proper function of CRAC channels is essential for immune responses and coordinated cellular activity.

Clinical and research relevance is significant because dysregulation of CRAC channel activity is linked to diseases such as immunodeficiencies, muscular disorders, and inflammatory conditions. Overactive or underactive CRAC signaling can disrupt cell function and homeostasis. As a result, CRAC channels are a target of pharmacological research, with efforts aimed at developing modulators that can temper immune responses or treat Ca2+-related pathologies.

Other uses: CRAC is an acronym that can have meanings beyond biology, depending on context. Because acronyms can be ambiguous, the intended meaning of CRAC should be inferred from the surrounding text or clarified with the source. This article focuses on the biological CRAC channel, while other uses are outside its scope.