Ayako Enomoto

Learn More
The C-4 hydroxylation of sphinganine and dihydroceramide is a rate-limiting reaction in the biosynthesis of phytosphingolipids. Mouse DES1 (MDES1) cDNA homologous to the Drosophila melanogaster degenerative spermatocyte gene-1 (des-1) cDNA leads to sphingosine Delta4-desaturase activity, and another mouse homologue, MDES2, has bifunctional activity,(More)
Des2 (degenerative spermatocyte 2) is a bifunctional enzyme that produces phytoceramide and ceramide from dihydroceramide. The molecular mechanism involved in C-4-hydroxylation has not been studied in detail. In the present paper, we report that C-4-hydroxylation requires an electron-transfer system that includes cytochrome b5 and that the hydroxylase(More)
Siglec-7, a sialic acid binding immunoglobulin-like lectin, predominantly transduces inhibitory signals through cytosolic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Here, we report that clustering of Siglec-7 with a specific F(ab')(2) elicited cell death. Interestingly, a truncated Siglec-7 lacking the cytosolic ITIM domain still induced the(More)
Although the amino acid sequences of mouse DES1 (MDES1) and DES2 (MDES2) have 63% sequence identity, their enzymatic characteristics are quite different. MDES1 exhibits high dihydroceramide delta4-desaturase activity and very low C-4 hydroxylase activity, while MDES2 is similarly active as both a dihydroceramide delta4-desaturase and a C-4 hydroxylase. We(More)
 In this study, we examined the therapeutic antitumor effect of cytotoxic T lymphocytes (CTL) generated against CD86-transfected mouse neuroblastoma C1300. We first generated the transfectant, CD86+C1300, expressing a high level of mouse CD86 on the cell surface. While CD86+C1300 cells were rejected in syngeneic A/J mice when inoculated subcutaneously,(More)
Selective growth inhibition against IL-6-dependent cells was detected in fermentation extracts of a microbial strain, K93-0711, which was characterized as Streptomyces species. Active metabolite, termed madindoline A and B, were isolated, and the structure was determined to be 3a-hydroxy-indoline with diketocyclopentene at the N position. Madindoline A and(More)
Staurosporine (1), a natural product first isolated by Omuraet al. l) from SaccPiarothrix aerocolonigenes subsp. staurosporeus AM-22822),was found to be a very potent inhibitor of protein kinase C (PKC) by Tamaoki et al.3\ Subsequently, 1 was found to have various pharmacological effects such as inhibition of platelet aggregation4), smooth muscle(More)
  • 1