sgk-1;skn-1

Serine/threonine-protein kinase sgk-1

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Locus: CELE_W10G6.2

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Wormbase description: sgk-1 encodes a serine/threonine protein kinase that is orthologous to the mammalian serum- and glucocorticoid-inducible kinases (SGKs); in C. elegans, sgk-1 activity is required for normal egg laying, generation time, stress response, and adult life span; SGK-1 forms a complex with the AKT kinases with which it functions in parallel to mediate certain aspects of DAF-2/insulin-signaling; SGK-1 phosphorylates DAF-16 in vitro in a manner strictly dependent upon pdk-1 which encodes a 3-phosphoinositide-dependent kinase; an SGK-1::GFP fusion protein is expressed beginning in late embryonic stages and in larvae is seen in sensory and motor neurons as well as in the intestine; in neurons SGK-1::GFP localizes to the cytoplasm and the nucleus, while in the intestine SGK-1::GFP is found exclusively in the cytoplasm.

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Protein skinhead-1;SKiNhead

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Locus: CELE_T19E7.2

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Wormbase description: skn-1 encodes a bZip transcription factor orthologous to the mammalian Nrf (Nuclear factor-erythroid-related factor) transcription factors; during early embryogenesis, maternally provided SKN-1 is required for specification of the EMS blastomere, a mesendodermal precursor that gives rise to pharyngeal, muscle, and intestinal cells; later, during postembryonic development, SKN-1 functions in the p38 MAPK pathway to regulate the oxidative stress response and in parallel to DAF-16/FOXO in the DAF-2-mediated insulin/IGF-1-like signaling pathway to regulate adult lifespan; in vitro assays indicate that SKN-1 can be directly phosphorylated by the AKT-1, AKT-2, and SGK-1 kinases that lie downstream of DAF-2 in the insulin signaling pathway and in vivo experiments suggest that this phosphorylation is essential for regulation of SKN-1 nuclear accumulation and hence, transcriptional regulator activity; in the early embryo, SKN-1 is detected at highest levels in nuclei of the P1 blastomere and its descendants through the 8-cell stage of embryogenesis; later in embryogenesis, SKN-1 is observed in all hypodermal and intestinal nuclei, with reporter constructs indicating that intestinal expression begins as early as the 50-100-cell stage; in larvae and young adults, SKN-1::GFP reporters are expressed in the intestine and ASI neurons, with expression in intestinal nuclei enhanced under conditions of stress or reduced DAF-2 signaling.

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