Calcium release-activated channel regulator 2A (CRACR2A)

Calcium release-activated channel regulator 2A (CRACR2A) is a multifunctional protein with an N-terminal EF-hand calcium-binding domain and a C-terminal Rab GTPase domain[1][2][3]. In T cells, CRACR2A acts as a molecular integrator of calcium signals, directly interacting with STIM1 (the ER calcium sensor) and Orai1 (the plasma membrane CRAC channel pore subunit) to facilitate their clustering and activation upon ER calcium depletion. This process ensures robust store-operated calcium entry (SOCE), which is essential for T cell activation and immune function[1][2][3][5]. CRACR2A is also involved in positive regulation of the JNK signaling cascade via interactions with adaptor proteins like Vav1[1]. Beyond immune cells, in endothelial cells, the long CRACR2A isoform (Rab46) participates in vesicular trafficking, specifically mediating calcium-dependent release of cargo from Weibel–Palade bodies and endothelial tube formation[2][3]. Mutations in CRACR2A impair SOCE and produce defects in cytokine secretion and T cell proliferation, underpinning immunodeficiency. CRACR2A's function as a calcium sensor and signal transducer makes it a critical component of both immune and vascular biology, though no drugs currently target it directly[1][2][3][5].

Other names

EF-hand calcium-binding domain-containing protein 4BEFCAB4BRab46Ras-related protein Rab-46Ca2+ release-activated Ca2+ (CRAC) channel regulator 2ACRAC channel regulator 2ACalcium release-activated calcium channel regulator 2AMGC4266EFC4B

Drugs that would target CRACR2A (theoretically) might: - Modulate SOCE via stabilization or disruption of ORAI1-STIM1 complex formation - Regulate downstream T cell activation and cytokine production (Such mechanisms are indirect, as no approved drugs for CRACR2A are listed)