CGC Bibliography Paper 3173

Caenorhabditis elegans Akt/PKB transduces insulin receptor-like signals from AGE-1 PI3 kinase to the DAF-16 transcription factor.

Paradis S, Ruvkun G

Medline:

98382502

Citation:

Genes & Development 12: 2488-2498 1998

Type:

ARTICLE

Genes:

age-1 akt-1 akt-2 daf-2 daf-3 daf-16

Abstract:

A neurosecretory pathway regulates a reversible developmental arrest and metabolic shift at the Caenorhabditis elegans dauer larval stage, Defects in an insulin-like signaling pathway cause arrest at the dauer stage. We show here that two C. elegans Akt/PKB homologs, akr-l and akt-2, transduce insulin receptor-like signals that inhibit dauer arrest and that AKT-1 and AKT-2 signaling are indispensable for insulin receptor-like signaling in C. elegans, A loss-of-function mutation in the Pork head transcription factor DAF-16 relieves the requirement far Akt/PKB signaling, which indicates that AKT-1 and AKT-2 function primarily to antagonize DAF-16. This is the first evidence that the major target of Akt/PKB signaling is a transcription factor. An activating mutation in akt-1, revealed by a genetic screen, as well as increased dosage of wild-type akt-1 relieves the requirement for signaling from AGE-1 PI3K, which acts downstream of the DAF-2 insulin/IGF-1 receptor homolog. This demonstrates that Akt/PKB activity is not necessarily dependent on AGE-1 PI3K activity. akt-1 and akt-2 are expressed in overlapping patterns In the nervous system and in tissues that are remodeled during dauer formation.