The LIM-Homeodomain Protein Islet Dictates Motor Neuron Electrical Properties by Regulating K+ Channel Expression
| Autor: | Andrea H. Brand, Tony D. Southall, Verena Wolfram, Richard A. Baines |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Central Nervous System
Embryo Nonmammalian Patch-Clamp Techniques Neuroscience(all) Green Fluorescent Proteins Neurotoxins Biophysics Biology Article Membrane Potentials Animals Genetically Modified 03 medical and health sciences 0302 clinical medicine medicine Animals Drosophila Proteins Transcription factor 030304 developmental biology Elapid Venoms Homeodomain Proteins Motor Neurons 0303 health sciences geography geography.geographical_feature_category Muscles musculoskeletal neural and ocular physiology General Neuroscience Gene Expression Regulation Developmental Motor neuron Islet Electric Stimulation medicine.anatomical_structure nervous system Larva embryonic structures Shaker Superfamily of Potassium Channels Homeobox Calcium Drosophila Axon guidance Neuron Ion Channel Gating Neuroscience 030217 neurology & neurosurgery Drosophila Protein Function (biology) Protein Binding |
| Zdroj: | Neuron |
| Popis: | Summary Neuron electrical properties are critical to function and generally subtype specific, as are patterns of axonal and dendritic projections. Specification of motoneuron morphology and axon pathfinding has been studied extensively, implicating the combinatorial action of Lim-homeodomain transcription factors. However, the specification of electrical properties is not understood. Here, we address the key issues of whether the same transcription factors that specify morphology also determine subtype specific electrical properties. We show that Drosophila motoneuron subtypes express different K+ currents and that these are regulated by the conserved Lim-homeodomain transcription factor Islet. Specifically, Islet is sufficient to repress a Shaker-mediated A-type K+ current, most likely due to a direct transcriptional effect. A reduction in Shaker increases the frequency of action potential firing. Our results demonstrate the deterministic role of Islet on the excitability patterns characteristic of motoneuron subtypes. Highlights ► Embryonic motoneurons show subtype-specific electrical properties ► Common developmental mechanisms predetermine morphology and electrical properties ► Islet suppresses A-type K+ channel expression in ventral motoneurons ► Absence of the A-type K+ channel increases action potential firing frequency Wolfram et al. report that early expression of the Lim-homeodomain transcription factor Islet represses the Shaker-dependent fast potassium channel in developing motoneurons. This is indicative that subtype-specific electrical properties in developing neurons are set by intrinsic mechanisms. |
| Databáze: | OpenAIRE |
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