Targets of TGF-beta signaling in Caenorhabditis elegans dauer formation

Citation
T. Inoue et Jh. Thomas, Targets of TGF-beta signaling in Caenorhabditis elegans dauer formation, DEVELOP BIO, 217(1), 2000, pp. 192-204
Citations number
70
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
DEVELOPMENTAL BIOLOGY
ISSN journal
0012-1606 → ACNP
Volume
217
Issue
1
Year of publication
2000
Pages
192 - 204
Database
ISI
SICI code
0012-1606(20000101)217:1<192:TOTSIC>2.0.ZU;2-2
Abstract
Caenorhabditis elegans dauer formation is controlled by multiple environmen tal factors. The chemosensory neuron ASI regulates dauer formation by secre tion of DAF-7/TGF-beta, but the molecular targets of the DAF-7 ligand are i ncompletely defined and the cellular targets are unknown. We genetically ch aracterized and cloned a putative transducer of DAF-7 signaling called daf- 14 and found that it encodes a Smad protein. DAF-14 Smad has a highly unusu al structure completely lacking the N-terminal domain found in all other Sm ad proteins known to date, daf-14 genetically interacts with daf-8, which e ncodes another Smad, and the interaction suggests partial functional redund ancy between these two Smad proteins. We also studied the cellular targets of DAF-7 signaling by studying the sites of action of daf-14 and daf-4, the putative receptor for DAF-7. daf-14::gfp is expressed in multiple tissues that are remodeled during dauer formation. However, analysis of mosaics gen erated by free duplication loss and tissue-specific expression constructs i ndicate cell-nonautonomous function of daf-e arguing against direct DAF-7 s ignaling to tissues throughout the animal. Instead, these experiments sugge st the nervous system as a target of DAF-7 signaling and that the nervous s ystem in turn regulates dauer formation by Other tissues. (C) 2000 Academic Press.