Figure 1.

CHIP Modulates Lifespan via Increased Insulin Signaling

(A) C. elegans chn-1 mutants (by155 and tm2692) exhibit short lifespans.

(B) Body size of chn-1 deficient worms is reduced, compared to wild-type worms (mean values ± SEM were obtained by measuring at least n = 20 worms). ^∗∗∗p < 0.001.

(C) Deletion of chn-1 shortens lifespan of eat-2(ad465) worms.

(D and E) DAF-16::GFP overexpression extends the lifespan of chn-1(by155) and chn-1(tm2692) worms.

(F) Depletion of daf-16 by RNAi shortens the lifespan of chn-1(by155) worms.

(G) chn-1 deficient worms exhibit delayed nuclear localization of DAF-16::GFP triggered by heat stress. DAF-16::GFP localization in wild-type, chn-1(by155) mutant worms, and worms overexpressing chn-1 (CHN-1::FLAG) was scored as nuclear or diffuse cytoplasmic (nuclear and cytoplasmic). Individual worms were classified based on the intracellular distribution of the DAF-16::GFP fluorescence. Data shown are from one representative experiment (n = 100).

(H) CHN-1 is important for efficient activation of DAF-16. Real-time PCR identified reduced levels of sod-3 and sip-1 mRNAs in worms lacking chn-1, similar to the daf-16 loss-of-function mutant (mean values were obtained in n = 3 independent biological replicates).

(I) Ubiquitous depletion of dCHIP through RNAi causes reduced lifespan of flies.

(J) Loss of dCHIP activates AKT signaling (S505, p-AKT) and stabilizes dINSR in flies (mean values were obtained in n = 5 independent experiments).

(K) Depletion of CHIP in HEK293 cells activates AKT signaling (phosphorylated AKT [S473, p-AKT] was quantified from n = 5 independent experiments).

(H, J, and K) Data are means SEM. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001. See Table S1 for lifespan statistics.

See also Figure S1.