Distinct functions of nuclear and cytoplasmic calcium in the control of gene expression.
Calcium entry into neuronal cells through voltage or ligand-gated ion channels triggers neuronal activity-dependent gene expression critical for adaptive changes in the nervous system. Cytoplasmic calcium transients are often accompanied by an increase in the concentration of nuclear calcium, but the functional significance of such spatially distinct calcium signals is unknown. Here we show that gene expression is differentially controlled by nuclear and cytoplasmic calcium signals which enable a single second messenger to generate diverse transcriptional responses. We used nuclear microinjection of a non-diffusible calcium chelator to block increases in nuclear, but not cytoplasmic, calcium concentrations following activation of L-type voltage-gated calcium channels. We showed that increases in nuclear calcium concentration control calcium-activated gene expression mediated by the cyclic-AMP-response element (CRE), and demonstrated that the CRE-binding protein CREB can function as a nuclear calcium-responsive transcription factor. A second signalling pathway, activating transcription through the serum-response element (SRE), is triggered by a rise in cytoplasmic calcium and does not require an increase in nuclear calcium.
Hardingham
G E
GE
MRC Laboratory of Molecular Biology, Cambridge, UK.
Chawla
S
S
Johnson
C M
CM
Bading
H
H
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology*; D002614:Chelating Agents / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D003593:Cytoplasm / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D016762:Genes, fos; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D015290:Second Messenger Systems; D026362:Serum Response Factor; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D002120:Calcium Channel Agonists; D002614:Chelating Agents; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011758:Pyrroles; D026362:Serum Response Factor; D014157:Transcription Factors; C071658:FPL 64176; D004533:Egtazic Acid; D011189:Potassium Chloride; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium