TY - JOUR
T1 - Translocation across golgi vesicle membranes
T2 - A CHO glycosylation mutant deficient in CMP-sialic acid transport
AU - Deutscher, Susan L.
AU - Nuwayhid, Naziha
AU - Stanley, Pamela
AU - Briles, Eve Ida Barak
AU - Hirschberg, Carlos B.
N1 - Funding Information:
This work was supported by grants CA-30345 (P. S.), GM 30365 (C. B. H) from the National Institutes of Health, and BC-382 from the American Cancer Society (C. 8. H). P. S. is a Faculty Research Awardee of the American Cancer Society.
PY - 1984/12
Y1 - 1984/12
N2 - 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.
AB - 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.
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U2 - 10.1016/0092-8674(84)90007-2
DO - 10.1016/0092-8674(84)90007-2
M3 - Article
C2 - 6498937
AN - SCOPUS:0021702358
SN - 0092-8674
VL - 39
SP - 295
EP - 299
JO - Cell
JF - Cell
IS - 2 PART 1
ER -