Mechanism of UDP-sugar transport into intracellular vesicles. Occurrence of UDP-GlcNAc/UDP and UDP-Gal/UDP antiports.
The mechanism of translocation of UDP-GlcNAc, UDP-Gal and UDP-Glc into intracellular vesicles has been studied using thymocytes whose plasma membranes have been permeabilized with isotonic ammonium chloride. It has been previously shown that the intracellular vesicles have specific carriers for UDP-GlcNAc and UDP-Gal. We now report that the translocation of these two sugar nucleotides occurs via UDP-GlcNAc/UDP and UDP-Gal/UDP antiports. The entry of UDP-GlcNAc or UDP-Gal into vesicles was specifically dependent on the exit of UDP from these vesicles. In contrast, no antiport mechanism has been recovered with UDP-Glc for which no transport and accumulation into intracellular vesicles were observed.
D000818:Animals; D001692:Biological Transport; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D051379:Mice; D013950:Thymus Gland; D014500:Uracil Nucleotides / Q000378:metabolism*; D014529:Uridine / Q000378:metabolism; D014530:Uridine Diphosphate / Q000378:metabolism*; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*; D014532:Uridine Diphosphate Glucose / Q000378:metabolism*; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*; D014542:Uridine Monophosphate / Q000378:metabolism
D014500:Uracil Nucleotides; D014539:Uridine Diphosphate Sugars; D014531:Uridine Diphosphate Galactose; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid; D014537:Uridine Diphosphate N-Acetylglucosamine; D014530:Uridine Diphosphate; D014542:Uridine Monophosphate; D014532:Uridine Diphosphate Glucose; D014529:Uridine