NRSF causes cAMP-sensitive suppression of sodium current in cultured hippocampal neurons.
The neuron restrictive silencer factor (NRSF/REST) has been shown to bind to the promoters of many neuron-specific genes and is able to suppress transcription of Na(+) channels in PC12 cells, although its functional effect in terminally differentiated neurons is unknown. We constructed lentiviral vectors to express NRSF as a bicistronic message with green fluorescent protein (GFP) and followed infected hippocampal neurons in culture over a period of 1-2 wk. NRSF-expressing neurons showed a time-dependent suppression of Na(+) channel function as measured by whole cell electrophysiology. Suppression was reversed or prevented by the addition of membrane-permeable cAMP analogues and enhanced by cAMP antagonists but not affected by increasing protein expression with a viral enhancer. Secondary effects, including altered sensitivity to glutamate and GABA and reduced outward K(+) currents, were duplicated by culturing GFP-infected control neurons in TTX. The striking similarity of the phenotypes makes NRSF potentially useful as a genetic "silencer" and also suggests avenues of further exploration that may elucidate the transcription factor's in vivo role in neuronal plasticity.
Nadeau
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Division of Biology, California Institute of Technology, Pasadena, California 91125, USA. nadeau@mail2.jpl.nasa.gov
Lester
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HA
D000818:Animals; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D004553:Electric Conductivity; D004622:Embryo, Mammalian; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D020868:Gene Silencing / Q000502:physiology; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009474:Neurons / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000502:physiology; D012016:Reference Values; D012097:Repressor Proteins / Q000494:pharmacology / Q000502:physiology*; D026941:Sodium Channel Blockers; D015222:Sodium Channels / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014157:Transcription Factors / Q000494:pharmacology / Q000502:physiology*; D000099229:RE1-Silencing Transcription Factor
D000242:Cyclic AMP; D049452:Green Fluorescent Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D018091:Receptors, AMPA; D012097:Repressor Proteins; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin; D014157:Transcription Factors; D000099229:RE1-Silencing Transcription Factor