Orchestration of stepwise synaptic growth by K+ and Ca2+ channels in Drosophila.

Abstract

Synapse formation is tightly associated with neuronal excitability. We found striking synaptic overgrowth caused by Drosophila K(+)-channel mutations of the seizure and slowpoke genes, encoding Erg and Ca(2+)-activated large-conductance (BK) channels, respectively. These mutants display two distinct patterns of "satellite" budding from larval motor terminus synaptic boutons. Double-mutant analysis indicates that BK and Erg K(+) channels interact with separate sets of synaptic proteins to affect distinct growth steps. Post-synaptic L-type Ca(2+) channels, Dmca1D, and PSD-95-like scaffold protein, Discs large, are required for satellite budding induced by slowpoke and seizure mutations. Pre-synaptic cacophony Ca(2+) channels and the NCAM-like adhesion molecule, Fasciclin II, take part in a maturation step that is partially arrested by seizure mutations. Importantly, slowpoke and seizure satellites were both suppressed by rutabaga mutations that disrupt Ca(2+)/CaM-dependent adenylyl cyclase, demonstrating a convergence of K(+) channels of different functional categories in regulation of excitability-dependent Ca(2+) influx for triggering cAMP-mediated growth plasticity.

• Authors: Jihye Lee, Chun-Fang Wu
• Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci) Vol. 30 Issue 47 Pg. 15821-33 (Nov 24 2010) ISSN: 1529-2401 [Electronic] United States
• PMID: 21106821 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Calcium Channels
• Drosophila Proteins
• Large-Conductance Calcium-Activated Potassium Channels
• Potassium Channels
• slo protein, Drosophila

Topics

• Animals
• Animals, Genetically Modified
• Calcium Channels (genetics, physiology)
• Drosophila Proteins (genetics, physiology)
• Drosophila melanogaster (genetics, growth & development)
• Large-Conductance Calcium-Activated Potassium Channels (genetics, physiology)
• Larva (genetics, growth & development)
• Mutation
• Potassium Channels (genetics, physiology)
• Synapses (genetics, physiology)