Fig 1: Mitochondrial membrane rearrangements are critical in recruiting p17/PERMIT‐CerS1 to mitochondria. (a) CerS1, and ICT1 in the whole lysate (WL) and mitochondrial fractions in vehicle (left) or SoSe (right) treated UM‐SCC‐1A cells. (b and c) Quantification of (a). Data are means ± SD (n = 3 independent experiments, **p < 0.01; ***p < 0.001). Normalization was done using corresponding protein levels. (d) Drp1 in cells treated with SCR control and Drp1 shRNA (left). Levels of ICT1 (top) and NUBPL (bottom) proteins in mitochondria isolated from SCR control and shDrp1 UM‐SCC‐1A cells treated with vehicle (−) or SoSe (+), 10 µM 3 h (right panel). (e and f) Quantification of (d). Data are means ± SD (n = 3 independent experiments, nsp > 0.5; **p < 0.01). (g) Representative Western Blot of Co‐IP analysis of ICT1 and p17 interaction in UM‐SCC‐1A cells with silenced endogenous p17 ectopically expressing empty vector (EV), wild type of p17 (WT) and p17RYE/AAA. (h) Quantification of p17/ICT1 interaction in cells from (g). Data are means ± SD (n = 3 independent experiments, ***p < 0.001). (i) Levels of p17WT and P17RYE/AAA mutant transiently expressed in p17 shRNA UM‐SCC‐1A cells. (j) ICT1 in UM‐SCC‐1A cells stably transfected with scrambled (Scr) or ICT1 shRNAs. (k) CerS1 and ICT1 in the whole lysates and mitochondrial fractions of Scr control and siICT1 RNA treated cells. (l) Confocal images of cells treated for 3 h with 10 μM of SoSe and stained for CerS1 (green) and MTR (red), mitochondrial marker. Yellow shows co‐localization. (m) Quantification of (l). Rc, the co‐localization coefficient was determined using Fiji J software. Images represent at least three independent experiments. Data are means ± SD (n = 3 independent experiments, **p < 0.01).