Metabolic pulse-chase and immunoprecipitation analysis of P-selectin in FL-derived megakaryocytes. Pulse-chase analysis of P-selectin expression in FL-derived megakaryocytes from WT or FOG1 ki/ki mice. (A) Representative autoradiograph of SDS-PAGE analysis of total megakaryocyte cell lysate input and immunoprecipitated P-selectin at 0 to 6 hours of chase after a 30-minute pulse with ³⁵S-methionine/cysteine. Positions of size markers are shown on left, and 2 arrows indicating the core glycosylated 126-kDa P-selectin precursor form (small arrow) and the 140-kDa P-selectin mature form (larger arrow) are shown on the right.²⁹  (B) P-selectin levels were quantified at each time point and calculated relative to the total amount present at time 0 as a percentage. □ represent WT; and ●, ki/ki curve. Data are mean ± SD. N = 3.