The SKICH domain is essential for CIL-1 ER localization. (A) Representative confocal images of a transgenic worm expressing mCherry::SP12 and CIL-1::GFP driven by the hypodermal cell specific promoter. Scale bar: 10 µm. The pattern of CIL-1::GFP fluorescence is very similar to the pattern of the ER marker mCherry::SP12. Insets showing magnified view of the boxed region (scale bar: 2 µm). (B) Representative confocal images of transgenic worms expressing full-length CIL-1::GFP or a truncated from of CIL-1 lacking the SKICH domain, CIL-1(deSKICH)::GFP. While WT CIL-1 has the reticular distribution in cells expected for an ER protein, the truncated protein has a diffuse cytosolic localization. Scale bar: 10 µm.