Transfer of N-acetylglucosamine to endogenous glycoproteins in the nucleus and in non-nuclear membranes of rat hepatocytes: electrophoretic analysis of the endogenous acceptors.
The transfer of N-acetyl(14C)glucosamine from UDP-N-acetyl(14C)glucosamine to endogenous glycoproteins acceptors were studied comparatively in the nuclei and in the non-nuclear membranes of rat hepatocytes. Electrophoretic and autoradiographic analysis show that most of the glycoprotein acceptors of the nuclei differ from those of the non-nuclear membranes in terms of molecular weight. In addition, it may interesting to mention that in the nuclear fraction a 30% inhibition by tunicamycin is obtained for concentrations as low as 0.03 microM, whereas at this concentration no effect is detected in the non-nuclear membranes. In the presence of 0.2 microM tunicamycin, the inhibition does not go beyond 25% in the latter fraction but goes up to 80% in the former. The previous results demonstrate clearly that a particular glycosylation reaction occurs in the nucleus.
Galland
S
S
Laboratoire de Biochimie des Membranes, LBTM CNRS UM 380024, Université Claude Bernard, Lyon 1, Villeurbanne, France.
Degiuli
A
A
Frot-Coutaz
J
J
Got
R
R
D000117:Acetylglucosamine / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005944:Glucosamine / Q000031:analogs & derivatives*; D005964:Glucosyltransferases / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D017351:N-Acetylglucosaminyltransferases; D051381:Rats; D011919:Rats, Inbred Strains; D014415:Tunicamycin / Q000494:pharmacology
D006023:Glycoproteins; D014415:Tunicamycin; D005964:Glucosyltransferases; D017351:N-Acetylglucosaminyltransferases; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase; D005944:Glucosamine; D000117:Acetylglucosamine