Calcium oscillations in T-cells: mechanisms and consequences for gene expression.
[Ca(2+)](i) (intracellular Ca(2+) concentration) oscillations play a central role in the activation of T-lymphocytes by antigen. Oscillations in T-cells are absolutely dependent on Ca(2+) influx through store-operated CRAC channels (Ca(2+)-release-activated Ca(2+) channels), and evidence suggests that they arise from delayed interactions between these channels and Ca(2+) stores. Their potential functions have been explored by creating controlled [Ca(2+)](i) oscillations with pulses of Ca(2+) entry or pulses of Ins(1,4,5)P(3). Oscillations enhance both the efficiency and specificity of signalling through the Ca(2+)-dependent transcription factors nuclear factor of activated T-cells (NFAT), Oct/Oap and nuclear factor kappa B (NF kappa B) in ways that are consistent with each factor's Ca(2+) dependence and kinetics of activation and deactivation. These studies show how [Ca(2+)](i) oscillations may enhance signalling to the nucleus, and suggest a possible cellular mechanism for extracting information encoded in oscillation frequency.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007700:Kinetics; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009991:Oscillometry; D010766:Phosphorylation; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium