Calcineurin activity is required for depolarization-induced, CREB-dependent gene transcription in cortical neurons

Authors

  • Tami J. Kingsbury,

    1. Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • Linda L. Bambrick,

    1. Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
    2. Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
    3. Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • Clinton D. Roby,

    1. Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author
  • Bruce K. Krueger

    1. Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
    2. Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
    Search for more papers by this author

Address correspondence and reprint requests to Tami Kingsbury, Department of Physiology, Bressler Research Building, 655 West Baltimore St, Baltimore, MD 21201, USA.
E-mail: tking001@umaryland.edu

Abstract

Cyclic AMP response element binding protein (CREB) functions as an activity-dependent transcription factor in the nervous system. Increases in intracellular Ca2+ due to neuronal activity lead to the phosphorylation and subsequent activation of CREB. Although phosphorylation of CREB at Ser-133 is necessary for the stimulation of transcriptional activity, it is not sufficient. Here we demonstrate that in mouse cortical neurons, inhibition of the Ca2+-dependent protein phosphatase calcineurin by FK506 or cyclosporine A blocks CREB-dependent gene expression induced by depolarization without inhibiting depolarization-induced Ca2+ influx or CREB Ser-133 phosphorylation. Over-expression of a constitutively-active allele of the transducer of regulated CREB activity could not bypass the requirement for calcineurin activity. Stimulation of a CRE-luciferase reporter gene by depolarization was sensitive to FK506 throughout the entire time course of the transcriptional response, revealing that calcineurin activity is required to maintain CREB-dependent transcription. Stimulation of CRE-luciferase expression by forskolin and 8-Br-cAMP also required calcineurin activity. These results suggest that calcineurin functions as a critical determinant in shaping genome responses to CREB activation in cortical neurons.

Ancillary