Calcineurin activity is required for depolarization-induced, CREB-dependent gene transcription in cortical neurons.
Cyclic AMP response element binding protein (CREB) functions as an activity-dependent transcription factor in the nervous system. Increases in intracellular Ca(2+) 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 Ca(2+)-dependent protein phosphatase calcineurin by FK506 or cyclosporine A blocks CREB-dependent gene expression induced by depolarization without inhibiting depolarization-induced Ca(2+) 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.
Kingsbury
Tami J
TJ
Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. tking001@umaryland.edu
Bambrick
Linda L
LL
Roby
Clinton D
CD
Krueger
Bruce K
BK
D000818:Animals; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis / Q000235:genetics; D019703:Calcineurin / Q000378:metabolism*; D065095:Calcineurin Inhibitors; D002118:Calcium / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D000242:Cyclic AMP / Q000502:physiology; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D017930:Genes, Reporter / Q000187:drug effects; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D010766:Phosphorylation; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D020813:Receptor, trkB / Q000096:biosynthesis / Q000235:genetics; D016559:Tacrolimus / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
D019208:Brain-Derived Neurotrophic Factor; D065095:Calcineurin Inhibitors; C519509:Crtc1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D014157:Transcription Factors; D012313:RNA; D000242:Cyclic AMP; D008156:Luciferases; D020813:Receptor, trkB; D019703:Calcineurin; D002118:Calcium; D016559:Tacrolimus