TY - JOUR
T1 - Two functionally dependent acetylcholine subunits are encoded in a single Caenorhabditis elegans operon
AU - Treinin, Millet
AU - Gillo, Boaz
AU - Liebman, Lilach
AU - Chalfie, Martin
PY - 1998/12/22
Y1 - 1998/12/22
N2 - 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 deg3(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.
AB - 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 deg3(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.
UR - http://www.scopus.com/inward/record.url?scp=0032416725&partnerID=8YFLogxK
U2 - 10.1073/pnas.95.26.15492
DO - 10.1073/pnas.95.26.15492
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C2 - 9860996
AN - SCOPUS:0032416725
SN - 0027-8424
VL - 95
SP - 15492
EP - 15495
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
ER -