| First Author | Kumagai T | Year | 2010 |
| Journal | Glycoconj J | Volume | 27 |
| Issue | 7-9 | Pages | 685-95 |
| PubMed ID | 21057870 | Mgi Jnum | J:268018 |
| Mgi Id | MGI:6271275 | Doi | 10.1007/s10719-010-9313-2 |
| Citation | Kumagai T, et al. (2010) Involvement of murine beta-1,4-galactosyltransferase V in lactosylceramide biosynthesis. Glycoconj J 27(7-9):685-95 |
| abstractText | Human beta-1,4-galactosyltransferase (beta-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 beta-1,4-GalT V (B4galt5)-mutant mice. Analysis of expression levels of the beta-1,4-GalT I-VI genes revealed that the expression of the beta-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 beta-1,4-GalT genes. These MEF cells showed no apparent difference in their growth. When beta-1,4-GalT activities were determined towards GlcNAcbeta-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-[(3)H]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 beta-1,4-GalT V is involved in Lac-Cer biosynthesis. |
