PH-dependent changes of ganglioside biosynthesis in neuronal cell culture
Iber, H.; van Echten, G.; Klein, R.A.; Sandhoff, K.
European Journal of Cell Biology 52(2): 236-240
1990
ISSN/ISBN: 0171-9335 PMID: 2127915 Document Number: 351168
Ganglioside biosynthesis was studied in primary cultured murine cerebellar cells after labeling with [14C]galactose. A shift in biosynthesis from "a"-series to "b"-series gangliosides was observed after lowering the pH of the culture medium from 7.4 to 6.2; this effect was fully reversible on changing back to pH 7.4. The observed regulatory effect of pH is in accordance with a recent model of ganglioside biosynthesis. Sialyltransferase II (ST II), the first enzyme for biosynthesis of "b"-series gangliosides, is more active at pH 6.2 than Gal-NAc-transferase, the first enzyme for synthesis of "a"-series gangliosides, which is more active than sialyltransferase II at pH 7.4.