An unconventional TGFβ superfamily pathway plays a crucial role in the decision between dauer diapause and reproductive growth. We have studied the daf-5 gene, which, along with the daf-3 Smad gene, is antagonized by upstream receptors and receptor-regulated Smads. We show that DAF-5 is a novel member of the Sno/Ski superfamily that binds to DAF-3 Smad, suggesting that DAF-5, like Sno/Ski, is a regulator of transcription in a TGFβ superfamily signaling pathway. However, we present evidence that DAF-5 is an unconventional Sno/Ski protein, because DAF-5 acts as a co-factor, rather than an antagonist, of a Smad protein. We show that expressing DAF-5 in the nervous system rescues a daf-5 mutant, whereas muscle or hypodermal expression does not. Previous work suggested that DAF-5 and DAF-3 function in pharyngeal muscle to regulate gene expression, but our analysis of regulation of a pharynx specific promoter suggests otherwise. We present a model in which DAF-5 and DAF-3 control the production or release of a hormone from the nervous system by either regulating the expression of biosynthetic genes or by altering the connectivity or the differentiated state of neurons.
CITATION STYLE
da Graca, L. S., Zimmerman, K. K., Mitchell, M. C., Kozhan-Gorodetska, M., Sekiewicz, K., Morales, Y., & Patterson, G. I. (2004). DAF-5 is a SKi oncoprotein homolog that functions in a neuronal TGFβ pathway to regulate C. elegans dauer development. Development, 131(2), 435–446. https://doi.org/10.1242/dev.00922
Mendeley helps you to discover research relevant for your work.