Total metabolic flow of glycosphingolipid biosynthesis is regulated by UDP-GlcNAc:lactosylceramide beta 1-->3N-acetylglucosaminyltransferase and CMP-NeuAc:lactosylceramide alpha 2-->3 sialyltransferase in human hematopoietic cell line HL-60 during differentiation.

摘要: Abstract We have previously reported that ganglioside GM3 was remarkably increased during monocytoid differentiation of human myelogenous leukemia cell line HL-60 cells and neolacto series gangliosides (NeuAc-nLc) were enriched granulocytoid differentiation. In addition, differentiated into monocytic lineage by exogenous NeuAc-nLc. the present report, enzymatic bases glycosphingolipid biosynthesis in induced 12-O-tetradecanoylphorbol-13-acetate all-trans-retinoic acid investigated. The following results particular interest. (i) Lactosylceramide alpha 2-->3 sialyltransferase (GM3 synthase) up-regulated monocyte differentiation, while synthase level did not change granulocytic (ii) By contrast, lactosylceramide beta 1-->3N-acetylglucosaminyltransferase (Lc3Cer down-regulated activity Lc3Cer found to increase (iii) activities four downstream glycosyltransferases (for synthesis NeuAc-nLc) or remain unchanged These strongly suggested following. dramatic decrease NeuAc-nLc are consequences up-regulation down-regulation synthase, although enzymes ready catalyze their enzyme reactions. notable relative together with activation glycosyltransferases. suggest these two key upstream glycosyltransferases, play critical roles regulating This switching mechanism our previous findings, might be one most important parts determining system direction myeloid lineages.