Transport of CMP-N-glycoloylneuraminic acid into mouse liver Golgi vesicles.
CMP-Neu5Gc has been shown to be transported into mouse liver Golgi vesicles by a specific carrier the characteristics of which were investigated in detail. In the system employed, CMP-Neu5Gc enters the Golgi vesicles within 2 min; transport was saturable with high concentrations of the sugar-nucleotide and was dependent on temperature. A kinetic analysis gave an apparent Km of 1.3 microM and a maximal transport velocity of 335 pmol/mg protein per min. Almost identical values were obtained with CMP-Neu5Ac, under the same incubation conditions. Furthermore, the uptake of CMP-Neu5Gc was inhibited by CMP-Neu5Ac, a substrate analogue. Conversely, the uptake of CMP-Neu5Ac was inhibited by CMP-Neu5Gc to the same extent, leading to the conclusion that the transport of CMP-Neu5Ac and CMP-Neu5Gc is mediated by the same carrier molecule. This transport system for CMP-Neu5Gc involves both CMP and CMP-Neu5Gc since intravesicular CMP induced the entry of external CMP-Neu5Gc.
Lepers
A
A
Laboratoire de Chimie Biologique, Université des Sciences et Techniques de Lille, Villeneuve d'Ascq, France.
Shaw
L
L
Cacan
R
R
Schauer
R
R
Montreuil
J
J
Verbert
A
A
D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport; D003568:Cytidine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D003597:Cytosine Nucleotides / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D009438:Neuraminic Acids / Q000378:metabolism*; D012799:Sialyltransferases / Q000378:metabolism
D003597:Cytosine Nucleotides; D009438:Neuraminic Acids; C060603:cytidine monophosphate-N-glycoloylneuraminic acid; D012799:Sialyltransferases; D003568:Cytidine Monophosphate