• Media type: E-Article
  • Title: Two Functionally Dependent Acetylcholine Subunits are Encoded in a Single Caenorhabditis elegans Operon
  • Contributor: Treinin, Millet; Gillo, Boaz; Liebman, Lilach; Chalfie, Martin
  • Published: National Academy of Sciences of the United States of America, 1998
  • Published in: Proceedings of the National Academy of Sciences of the United States of America, 95 (1998) 26, Seite 15492-15495
  • Language: English
  • ISSN: 0027-8424
  • Origination:
  • Footnote:
  • Description: The deg-3 gene from the nematode Caenorhabditis elegans encodes an α subunit of a nicotinic acetylcholine receptor that was first identified by a dominant allele, u662, which produced neuronal degeneration. Because deg-3 cDNAs contain the SL2 trans-spliced leader, we suggested that deg-3 was transcribed as part of a C. elegans operon. Here we show that des-2, a gene in which mutations suppress deg-3(u662), is the upstream gene in that operon. The des-2 gene also encodes an α subunit of a nicotinic acetylcholine receptor. As expected for genes whose mRNAs are formed from a single transcript, both genes have similar expression patterns. This coexpression is functionally important because (i) des-2 is needed for the deg-3(u662) degenerations in vivo; (ii) an acetylcholine-gated channel is formed in Xenopus oocytes when both subunits are expressed but not when either is expressed alone; and (iii) channel activity, albeit apparently altered from that of the wild-type channel, results from the expression of a u662-type mutant subunit but, again, only when the wild-type DES-2 subunit is present. Thus, the operon structure appears to regulate the coordinate expression of two channel subunits.
  • Access State: Open Access