Regulation of UDP-glucose:ceramide glucosyltransferase-1 by ceramide.
We report that the expression of mRNA and the activity of UDP-glucose:ceramide (Cer) glucosyltransferase-1 (GlcT-1) of human hepatoma Huh7 and mouse melanoma B16 cells increases after treatment with bacterial sphingomyelinase or upon addition of short-chain Cer. Interestingly, however, GlcT-1 gene transcription was not increased by Cer when GlcT-1 cDNA was introduced with the CMV promoter in GlcT-1-deficient GM95 cells, suggesting that the normal promoter region of GlcT-1 gene is essential for the response. The conversion of C6-Cer to C6-GlcCer occurred much more rapidly in GlcT-1-overexpressing Huh7 cells than in mock transfectants. As a result, GlcT-1-overexpressing cells acquired a greater resistance to C6-Cer-mediated cell death.
Komori
H
H
Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
Ichikawa
S
S
Hirabayashi
Y
Y
Ito
M
M
D000818:Animals; D002518:Ceramides / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D002518:Ceramides; D018076:DNA, Complementary; D012333:RNA, Messenger; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase