Depletion of wildtype <i>csnk-1</i> transcripts in L4 <i>csnk-1(lf)</i> mutants.

(A) Positions and sequences of PCR primers for detecting all or wildtype-only csnk-1 transcripts. Partial wildtype and mutant csnk-1 sequences are aligned to show the specificity of the primers for wildtype-only transcripts. (B) Relative total csnk-1 transcript levels. (C, D) Relative wildtype-only csnk-1 transcript levels in wildtype, csnk-1(mac494lf) or csnk-1(mac495lf) animals. tba-1 was the loading control. Statistics: two-tailed unpaired Student’s t-test. *: p p p (TIFF)</p

<i>csnk-1(lf)</i> and <i>skn-1(gf)</i> mutations exhibit synergy on the Sisi phenotype in 50 mM NaI.

csnk-1(lf) and skn-1(gf) mutations exhibit synergy on the Sisi phenotype in 50 mM NaI.</p

Effects of <i>csnk-1</i> mutations or variable feeding RNAis on the Sisi phenotype.

Mammalian orthologs or homologs are indicated in the parentheses. (TIFF)</p

Effects of <i>csnk-1</i> transgenes on the Sisi phenotype of <i>csnk-1(lf)</i> mutants in 5 mM NaI.

Effects of csnk-1 transgenes on the Sisi phenotype of csnk-1(lf) mutants in 5 mM NaI.</p

Phenotypic analyses of <i>csnk-1(lf)</i> mutants.

(A) Number of all eggs laid per adult. Results were based three biological replicates, with three animals per replicate. Colors represent different replicates. Statistics: two-tailed unpaired Student’s t-test. *: p csnk-1(lf) homozygous mutants. All eggs laid by a single adult on regular NGM agar plates were examined. Results were based on three biological replicates, with three animals per replicate. Statistics: two-tailed unpaired Student’s t-test. ****: p csnk-1(lf) mutants. Arrows indicate attached cuticles. (E) Quantification of young adults (24 hrs after mid-L4 larval stage) with molting defects. Results were based on three biological replicates, with 100 animals analyzed in each replicate. Statistics: two-tailed unpaired Student’s t-test. **: p p csnk-1(lf)/+ and csnk-1(lf) mutants labeled by a DPY-7::sfGFP reporter. (H) Percentage of young adults positively stained by the nuclear dye Hoechst 33258. Results were based on three biological replicates, with 59–141 animals in each replicate. Statistics: two-tailed unpaired Student’s t-test. ****: p csnk-1(lf) L4 animals stained with DCFDA. Pictures were taken with the same exposure time of 600 ms and fluorescent intensity of each animal was measured using ImageJ. (K) Quantification of DCFDA fluorescent signals of individual L4 animals. Results were based on three biological replicates, with 21–100 animals in each replicate. Statistics: two-tailed unpaired Student’s t-test. ****: p (TIFF)</p

Nonallelic noncomplementation interaction between <i>csnk-1</i> and <i>tsp-15</i>, <i>bli-3</i> or <i>doxa-1</i>.

Nonallelic noncomplementation interaction between csnk-1 and tsp-15, bli-3 or doxa-1.</p

CSNK-1::mCherry does not colocalize with GFP and DOXA-1::GFP does not colocalize with mCherry.

(A, B, C) A transgenic L3 larvae co-expressing GFP and CSNK-1::mCherry in epithelial cells. (D, E, F) A transgenic 3-fold embryo co-expressing DOXA-1::GFP and mCherry in epithelial cells. For unclear reason, DOXA-1::GFP was strongly expressed in embryos but was not visible at larval stages in these transgenic lines. We therefore observed whether DOXA-1::GFP colocalizes with mCherry in embryos. (TIFF)</p

PCR primers for generating the listed DNA fragments.

PCR primers for generating the listed DNA fragments.</p

Representative morphologies of double homozygous mutants between <i>csnk-1(lf)</i> and <i>bli-3(lf)</i> or <i>doxa-1(lf)</i>.

bli-3(lf) csnk-1(lf) double homozygous mutants were derived from bli-3(lf) csnk-1(lf)/hT2 heterozygous mutants. csnk-1(lf); doxa-1(lf) double homozygous mutants were derived from csnk-1(lf)/hT2; doxa-1(lf)/hT2 heterozygous mutants. Arrows point to typical blisters. All images are of the same scale. (TIFF)</p

Raw data for Figures and Tables.

Oxidative stress response is a fundamental biological process mediated by conserved mechanisms. The identities and functions of some key regulators remain unknown. Here, we report a novel role of C. elegans casein kinase 1 gamma CSNK-1 (also known as CK1γ or CSNK1G) in regulating oxidative stress response and ROS levels. csnk-1 interacted with the bli-3/tsp-15/doxa-1 NADPH dual oxidase genes via genetic nonallelic noncomplementation to affect C. elegans survival in oxidative stress. The genetic interaction was supported by specific biochemical interactions between DOXA-1 and CSNK-1 and potentially between their human orthologs DUOXA2 and CSNK1G2. Consistently, CSNK-1 was required for normal ROS levels in C. elegans. CSNK1G2 and DUOXA2 each can promote ROS levels in human cells, effects that were suppressed by a small molecule casein kinase 1 inhibitor. We also detected genetic interactions between csnk-1 and skn-1 Nrf2 in oxidative stress response. Together, we propose that CSNK-1 CSNK1G defines a novel conserved regulatory mechanism for ROS homeostasis.</div