In order to gain information on the ability of the glycosylation system of Schizosaccharomyces pombe to process heterologous glycoproteins, the expression of Saccharomyces cerevisiae invertase in the former yeast was studied. Sc. pombe cells are able to produce enzymatically active invertase from the S. cerevisiae SUC2 gene introduced by transformation and the enzyme is glycosylated and secreted into the cell wall. However, Sc. pombe transformants do not glycosylate the heterologous enzyme as their own invertase since it is not bound by the lectin from Bandeiraea simplicifolia seeds, which indicates the absence of terminal galactose residues. Moreover, the electrophoretic mobility of the heterologous invertase is similar to that of the large enzyme from S. cerevisiae, both in its native form and after being deglycosylated with Endo H. These results suggest that the polypeptide chain of S. cerevisiae invertase is the primary factor for the glycosylation in Sc. pombe cells.