Worm Breeder's Gazette 14(3): 46 (June 1, 1996)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
Department of Physiology, The Hebrew University-Hadassah Medical School, P.O.B 12272, 91120 Jerusalem, Israel.
DEG-3 is an acetylcholine receptor alpha subunit that can mutate to cause neuronal degeneration. Molecular and pharmacological analysis suggest that deregulation of channel activity is the cause of the deg-3(u662) induced neuronal degeneration. However a more precise understanding of the degeneration causing changes requires electrophysiological analysis. As expression of deg-3 cDNA in Xenopus oocytes did not produce acetylcholine gated currents, additional subunits are probably needed for channel activity (1). Candidates for DEG-3 channel subunits where identified from genetic and molecular analysis. Extragenic suppressors of the deg-3(u662) mutation may code for additional subunits. Another candidate was obtained from molecular analysis; deg-3 message is trans-spliced to SL2, suggesting that it is part of a polycistronic transcription unit (2). Indeed sequencing upstream of deg-3 led us to a nearby gene also encoding for an acetylcholine receptor alpha subunit (3). The presence of two acetylcholine receptor subunits in the same cells, a finding supported by expression analysis, suggested that these two subunits may interact in forming a channel. Support for this proposal comes from electrophysiology in Xenopus oocytes. Expression of both genes produced acetylcholine dependent currents, while alone neither produce any detectable currents. Thus we have demonstrated a functional interaction between the two components of the deg-3 operon. This also provides us with a tool needed for the characterization of the normal and mutant DEG-3 channel. 1. Treinin and Chalfie (1995). Neuron 14, 871-877. 2. Spieth et al. (1993). Cell 73, 521-532. 3. Garcia-Anoveros et al. (1995) International C. elegans Meeting 75.