Rous Sarcoma Virus - transformed Baby Hamster Kidney Cells Express Higher Levels of Asparagine - linked Tri - and Tetraantennary Glycopeptides Containing

The alterations in complex-type N-linked oligosaccharides that can occur when an animal cell line is transformed by two dissimilar viruses were examined by comparing the N-linked oligosaccharides of baby hamster kidney (BHK) cells, metabolically radiolabeled with [2-’H]mannose, to the same class of oligosaccharides from BHK cells separately transformed by Rous sarcoma virus (RS-BHK), an RNA retrovirus, and polyoma virus (PY-BHK), a DNA papovavirus. Based on experiments that utilized serial lectin affinity chromatography, glycosidase digestions, and methylation analyses, both RS-BHK and PY-BHK cells demonstrated a significant increase in the relative amounts of triand tetraantennary complex-type N-linked oligosaccharides containing the branching sequence, [GlcNAc-j3( 1,G)Man-a( 1,6)Man], compared to the nontransformed BHK cells. In addition, almost all of the poly-N-acetyllactosamine sequence, [GlcNAc-j3(1,3)Gal-j3(1,4)], was expressed on the triand tetraantennary N-linked oligosaccharides from BHK and RSBHK cells that contain the sequence, [GlcNAc,B(l,G)Man-j3(1,6)Man]. The increase in the relative amounts of this latter sequence in the transformed cells, therefore, most likely results in an increase in the amount of poly-N-acetyllactosamine sequence on the N-linked glycopeptides of these cells. The analysis of the degree of sialylation of the complex-type Nlinked oligosaccharides from BHK and RS-BHK cells by ion exchange chromatography revealed no apparent differences, and in both of these cell types approximately 3% of the glycopeptide fraction radiolabeled with mannose was recovered in a highly negatively charged fraction that was identified by keratanase digestion to be keratan sulfate.