title: Orai1-NFAT signalling pathway triggered by T cell receptor stimulation.
abstract: T cell receptor (TCR) stimulation plays a crucial role in development, homeostasis, proliferation, cell death, cytokine production, and differentiation of T cells. Thus, in depth understanding of TCR signalling is crucial for development of therapy targeting inflammatory diseases, improvement of vaccination efficiency, and cancer therapy utilizing T cell-based strategies. TCR activation turns on various signalling pathways, one of the important one being the Ca(2+)-calcineurin-nuclear factor of activated T cells (NFAT) signalling pathway. Stimulation of TCRs triggers depletion of intracellular Ca(2+) store and in turn, initiates store-operated Ca(2+) entry (SOCE), one of the major mechanisms to raise the intracellular Ca(2+) concentrations in T cells. Ca(2+)-release-activated-Ca(2+) (CRAC) channels are a prototype of store-operated Ca(2+) (SOC) channels in immune cells that are very well characterized. Recent identification of STIM1 as the endoplasmic reticulum (ER) Ca(2+) sensor and Orai1 as the pore subunit has dramatically advanced the understanding of CRAC channels and provides a molecular tool to investigate the physiological outcomes of Ca(2+) signalling during immune responses. In this review, we focus on our current understanding of CRAC channel activation, regulation, and downstream calcineurin-NFAT signaling pathway.
authors.affiliation: Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
authors.forename: Sonal
authors.initials: S
authors.lastname: Srikanth
authors.forename: Yousang
authors.initials: Y
authors.lastname: Gwack
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D020013:Calcium Signaling; D006801:Humans; D008213:Lymphocyte Activation; D050778:NFATC Transcription Factors / Q000502:physiology*; D000071740:ORAI1 Protein; D011499:Protein Processing, Post-Translational; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D050778:NFATC Transcription Factors; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D011948:Receptors, Antigen, T-Cell