Translocation across golgi vesicle membranes: A CHO glycosylation mutant deficient in CMP-sialic acid transport

Susan L. Deutscher, Naziha Nuwayhid, Pamela Stanley, Eve Ida Barak Briles, Carlos B. Hirschberg

Research output: Contribution to journalArticle

187 Scopus citations


Golgi vesicle membranes from the Lec2 CHO glycosylation mutant translocate CMP-sialic acid at only 2% the rate of vesicles from wild-type CHO cells. The deficiency is specific, because vesicles from Lec2 cells can translocate UDP-N-acetylglucosamine, adenosine 3′-phosphate 5′-phosphosulfate, and UDP-galactose at rates comparable to those of vesicles from wild-type cells. Complementation analyses show that Lec2 mutants belong to the same genetic complementation group as clone 1021, a CHO mutant of similar phenotype. Both mutants have previously been shown to have a 90% reduction in the sialylation of glycoproteins and gangliosides compared with wild-type cells. However, 1021 cells appear to have normal levels of CMP-sialic acid, sialyltransferase activity, and endogenous acceptors for sialylation. It seems likely that the primary defect in Lec2 and 1021 cells is their inability to translocate CMP-sialic acid across Golgi vesicle membranes.

Original languageEnglish (US)
Pages (from-to)295-299
Number of pages5
Issue number2 PART 1
StatePublished - Dec 1984


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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