TY - JOUR
T1 - Involvement of murine β-1,4-galactosyltransferase v in lactosylceramide biosynthesis
AU - Kumagai, Tadahiro
AU - Sato, Takeshi
AU - Natsuka, Shunji
AU - Kobayashi, Yukito
AU - Zhou, Dapeng
AU - Shinkai, Tadashi
AU - Hayakawa, Satoru
AU - Furukawa, Kiyoshi
N1 - Funding Information:
Acknowledgments This work was supported by Grants-in-Aid for Scientific Research (09240104, 12680708 and 22370048) from the Ministry of Education, Science, Culture and Sports of Japan, and the Research Promotion Fund from the Japan Science Technology Agency (2007-2009) to KF.
PY - 2010/10
Y1 - 2010/10
N2 - Human β-1,4-galactosyltransferase (β-1,4-GalT) V was shown to be involved in the biosynthesis of N-glycans, O-glycans and lactosylceramide (Lac-Cer) by in vitro studies. To determine its substrate specificity, enzymatic activity and its products were analyzed using mouse embryonic fibroblast (MEF) cells from β-1,4-GalT V (B4galt5)-mutant mice. Analysis of expression levels of the β-1,4-GalT I-VI genes revealed that the expression of the β-1,4-GalT V gene in B4galt5 +/- - and B4galt5 -/- -derived MEF cells are a half and null when compared to that of B4galt5 +/+ -derived MEF cells without altering the expression levels of other β-1,4-GalT genes. These MEF cells showed no apparent difference in their growth. When β-1,4-GalT activities were determined towards GlcNAcβ-S-pNP, no significant difference in its specific activity was obtained among B4galt5 +/+ -, B4galt5 +/- - and B4galt5 -/- -derived MEF cells. No significant differences were obtained in structures and amounts of N-glycans and lectin bindings to membrane glycoproteins among B4galt5 +/+ -, B4galt5 +/- - and B4galt5 -/- -derived MEF cells. However, when cell homogenates were incubated with glucosylceramide in the presence of UDP-[3H]Gal, Lac-Cer synthase activity in B4galt5 +/- - and B4galt5 -/- -derived MEF cells decreased to 41% and 11% of that of B4galt5 +/+ -derived MEF cells. Consistent with this, amounts of Lac-Cer and its derivative GM3 in B4galt5 -/- -derived MEF cells decreased remarkably when compared with those of B4galt5 +/+ -derived MEF cells. These results indicate that murine β-1,4-GalT V is involved in Lac-Cer biosynthesis.
AB - Human β-1,4-galactosyltransferase (β-1,4-GalT) V was shown to be involved in the biosynthesis of N-glycans, O-glycans and lactosylceramide (Lac-Cer) by in vitro studies. To determine its substrate specificity, enzymatic activity and its products were analyzed using mouse embryonic fibroblast (MEF) cells from β-1,4-GalT V (B4galt5)-mutant mice. Analysis of expression levels of the β-1,4-GalT I-VI genes revealed that the expression of the β-1,4-GalT V gene in B4galt5 +/- - and B4galt5 -/- -derived MEF cells are a half and null when compared to that of B4galt5 +/+ -derived MEF cells without altering the expression levels of other β-1,4-GalT genes. These MEF cells showed no apparent difference in their growth. When β-1,4-GalT activities were determined towards GlcNAcβ-S-pNP, no significant difference in its specific activity was obtained among B4galt5 +/+ -, B4galt5 +/- - and B4galt5 -/- -derived MEF cells. No significant differences were obtained in structures and amounts of N-glycans and lectin bindings to membrane glycoproteins among B4galt5 +/+ -, B4galt5 +/- - and B4galt5 -/- -derived MEF cells. However, when cell homogenates were incubated with glucosylceramide in the presence of UDP-[3H]Gal, Lac-Cer synthase activity in B4galt5 +/- - and B4galt5 -/- -derived MEF cells decreased to 41% and 11% of that of B4galt5 +/+ -derived MEF cells. Consistent with this, amounts of Lac-Cer and its derivative GM3 in B4galt5 -/- -derived MEF cells decreased remarkably when compared with those of B4galt5 +/+ -derived MEF cells. These results indicate that murine β-1,4-GalT V is involved in Lac-Cer biosynthesis.
KW - B4galt5 mice
KW - Lactosylceramide
KW - MEF cells
KW - β-1,4-GalT V
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U2 - 10.1007/s10719-010-9313-2
DO - 10.1007/s10719-010-9313-2
M3 - Article
C2 - 21057870
AN - SCOPUS:78651234929
VL - 27
SP - 685
EP - 695
JO - Glycoconjugate Journal
JF - Glycoconjugate Journal
SN - 0282-0080
IS - 7-9
ER -