Fig 3. The ID-associated de novo mutation in CERT1 affects the phosphorylation status of CERT in LCLs.

(A) The trio-derived LCLs were analyzed by Western blotting with the indicated primary antibodies. Hyperphosphorylated (hyper-p-) and de/hypophosphorylated (d/hypo-) CERT are shown (left). The de/hypophosphorylated levels of CERT in the trio-derived LCLs were quantified by densitometric scanning of the band intensities (right). The data comprise the mean ± SEM; n = 3 (**, p < 0.01; n.s., not significant). (B) Trio LCL lysates were incubated with or without λPPase and analyzed by Western blotting with the indicated primary antibodies. The white and black arrowheads represent completely de/hypophosphorylated CERT and CERT/L, respectively. (C) Trio LCLs were cultured with L-[U-¹⁴C]serine for 16 hr. Metabolically labelled lipids separated on a TLC plate were visualized (representative image, left) and labelled SM was quantified (right). PE, phosphatidylethanolamine; PS, phosphatidylserine. The data comprise the mean ± SEM; n = 4.