Alteration of glycosyltransferase activities during proliferation of cultivated arterial endothelial cells and smooth muscle cells.
The activities of glycosyltransferases involved in the biosynthesis of N-linked glycans of glycoproteins in cultivated endothelial and smooth muscle cells have been analysed. Both cell types contain galactosyl-, N-acetylglucosaminyl-, sialyl- and fucosyltransferases in decreasing order of activity, but the specific enzyme activity of glycosyltransferases is higher in endothelial cells. These differences are due neither to elevated glycosidase activities nor to enhanced hydrolysis of nucleotide sugars. Cell growth and differentiation have substantial influence on glycosyltransferase expression. Within 5 days after plating of endothelial cells all glycosyltransferase activities increase 3-10-fold. The highest activities are found in confluent cultures. In smooth muscle cells, however, the activities of all transferases except N-acetylglucosaminyltransferase, whose activity does not change during the logarithmic growth phase, increase by only 20-50%. Glycosidases are subject to variations but the specific activities are not strictly correlated to cell proliferation. Four days after the beginning of cultivation the activities of alpha-fucosidase and beta-N-acetylhexosaminidase are at a minimum in endothelial cells, whereas the activities of these enzymes attain their maxima in smooth muscle cells. The results suggest that the biosynthesis of glycoproteins in endothelial and smooth muscle cells is subject to growth-dependent regulation. Thus, substantial alterations of the cellular glycoprotein pattern are expected to occur during cell proliferation.
Vischer
P
P
Buddecke
E
E
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000201:enzymology*; D005647:Fucosyltransferases / Q000378:metabolism; D005700:Galactosyltransferases / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism; D006602:Hexosyltransferases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology*; D017351:N-Acetylglucosaminyltransferases; D012799:Sialyltransferases / Q000378:metabolism; D013552:Swine
D005647:Fucosyltransferases; D005700:Galactosyltransferases; D005964:Glucosyltransferases; D006602:Hexosyltransferases; D017351:N-Acetylglucosaminyltransferases; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase; D012799:Sialyltransferases