Vesicular transport of sulfatide in the myelinating mouse brain. Functional association with lysosomes

摘要: Sulfatide synthesis and its subcellular distribution kinetics was followed in the myelinating brain of 17-day-old mice. Pulse-labeling-chasing conditions were achieved by an intraperitoneal injection (35S)sulfate 2 h later a second high dose unlabeled sulfate. At 1, 2, 3, 4, 6 after injection, brains removed, homogenized, fractions obtained differential discontinuous sucrose gradient centrifugation (Eichberg, J., Whittaker, V. P., Dawson, R. M. (1964) Biochem. J. 92, 91-100). The microsomal membranes further subfractionated (Siegrist, H. Burkart, T., Wiesmann, U. N., Herschkowitz, N. Spycher, A. (1979) Neurochem. 33, 497-504) into light myelin, plasma membranes, Golgi vesicles, endoplasmic reticulum heavy vesicles associated with acid hydrolase activities. [35S]sulfatide-labeling measured all fractions. results indicate that sulfatides are synthesized Golgi-endoplasmic complex transferred at least partially lysosomes to myelin membranes. association could explain existence previously described labile pool newly (Burkart, Hofmann, K., Siegrist, (1981) Dev. Biol. 83, 42-48) also be form vesicular transport myelin.