akt-1;akt-2;rrf-3;skn-1

Serine/threonine-protein kinase akt-1

Locus: CELE_C12D8.10

Wormbase description: akt-1 encodes an ortholog of the serine/threonine kinase Akt/PKB; akt-1 genetically interacts with the insulin signaling pathway and functions to regulate such processes as dauer larval development and salt chemotaxis learning; AKT-1 binds calmodulin in vitro in a calcium-dependent manner; an AKT-1::GFP fusion protein is widely expressed beginning in late stage embryos and continuing through adulthood; expression is seen in head, tail, and dorsal and ventral cord neurons, with additional expression seen in other cells including those of the pharynx, hypodermis, intestine, and spermatheca; two alleles of akt-1 (sa573 and sa700) have a Daf-c mutant phenotype at 27 degrees C (Hid phenotype).

Serine/threonine-protein kinase akt-2

Locus: CELE_F28H6.1

Wormbase description: akt-2 encodes a homolog of the serine/threonine kinase Akt/PKB, AKT-2, that is required for progression through the dauer stage of development and for the negative regulation of adult lifespan; inactivation of akt-2 causes animals to arrest constitutively at the dauer stage, while having an increased life span; widely expressed, AKT-2 is activated by the phospholipid products of phosphoinositide 3-kinase AGE-1/PI3K and by PDK-1, a homolog of vertebrate 3-phosphoinositide-dependent kinase-1 (PDK-1) Normal akt-2 (and akt-1) activity is required for excess pdk-1 activity to suppress the dauer-arrest phenotype of age-1, indicating that the 3-phosphoinositide-dependent kinase-1 homolog PDK-1 transduces signals from AGE-1 to AKT-2 (and AKT-1); conversely, the akt-2 loss-of-function phenotype is suppressed by daf-16 null mutations, indicating that the Fork head transcription factor DAF-16 is downstream of AKT-2 (and AKT-1), and that AKT-1 and AKT-2 act primarily to antagonize DAF-16.

RNA-dependent RNA polymerase Family

Locus: CELE_F10B5.7

Wormbase description: rrf-3 encodes an RNA-directed RNA polymerase (RdRP) homolog that inhibits somatic RNAi, and thus promotes activity of repeated genes (e.g., multicopy transgenic arrays); the effect of RRF-3 on RNAi is opposite to that of RRF-1 (which stimulates somatic RNAi), which might arise from competition by RRF-3 with RRF-1 or EGO-1 in RNAi formation; rrf-3(allele) or rrf-3(allele2) mutants are hypersensitive to somatic RNAi, and conversely suppress the activity of an integrated rol6 (su1006) transgene.

Protein skinhead-1;SKiNhead

Locus: CELE_T19E7.2

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.