1. (CSDB ID: 46293) | ![]() |
/Variants 1/-+ | /Variants 0/-b-D-Manp4(%)Ac6(%)Ac-(1-4)-D-Ery-ol /Variants 0/ is: Pam-(1-3)- OR (exclusively) Myr-(1-3)- OR (exclusively) Lau-(1-3)- OR (exclusively) C15-(1-3)- OR (exclusively) C13-(1-3)- /Variants 1/ is: Vl-(1-2)- OR (exclusively) Hxo-(1-2)- OR (exclusively) But-(1-2)- OR (exclusively) Pp-2)- OR (exclusively) Ac-2)- | Show graphically |
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Ustilago maydis
(NCBI TaxID 5270,
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Many microorganisms secrete surface-active glycolipids. The basidiomycetous fungus Ustilago maydis produces two different classes of glycolipids, mannosylerythritol lipids (MEL) and ustilagic acids (UAs). Here we report that biosynthesis of MELs is partially localized in peroxisomes and coupled to peroxisomal fatty acid degradation. The acyltransferases, Mac1 and Mac2, which acylate mannosylerythritol with fatty acids of different length, contain a type 1 peroxisomal targeting signal (PTS1). We demonstrate that Mac1 and Mac2 are targeted to peroxisomes, while other enzymes involved in MEL production reside in different compartments. Mis-targeting of Mac1 and Mac2 to the cytosol did not block MEL synthesis but promoted production of MEL species with altered acylation pattern. This is in contrast to peroxisome deficient mutants that produced MELs similar to the wild type. We could show that cytosolic targeting of Mac1 and Mac2 reduces the amount of UA presumably due to competition for overlapping substrates. Interestingly, hydroxylated fatty acids characteristic for UAs appear in MELs corroborating cross-talk between both biosynthesis pathways. Therefore, peroxisomal localization of MEL biosynthesis is not only prerequisite for generation of the natural spectrum of MELs, but also facilitates simultaneous assembly of different glycolipids in a single cell.
mannosylerythritol lipid, Pseudozyma flocculosa, extracellular glycolipid
Structure type: monomer ; 720-760lXVl(1-2)[%Ac(1-6),%Ac(1-4),lXPam(1-3)]bDManp(1-4)xDEry-olThere is only one chemically distinct structure for the variant above:
2. (CSDB ID: 62844) | ![]() |
b-D-Glcp6Ac-(1-2)-b-D-Glcp-(1-3)-Subst Subst = (3β,12β,20E)-3,12-dihydroxydammara-20(22),24-dien = SMILES CC(C)=CC/C=C(\C)[C@H]1CC[C@]2(C)[C@@H]1{12}[C@@H](O)C[C@@H]1[C@@]3(C)CC{3}[C@@H](O)C(C)(C)C3CC[C@]12C | Show graphically |
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Panax ginseng
(NCBI TaxID 4054,
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In this paper, we present evidence that ginsenoside-Rs4 (G-Rs4; an acetylated analogue of ginsenoside-Rg5), a new ginseng saponin isolated from Panax ginseng C. A. Meyer, elevates protein levels of p53 and p21WAF1, which are associated with the induction of apoptosis in SK-HEP-1 cells. Flow cytometric analyses showed that G-Rs4 initially arrested the cell cycle at the G1/S boundary, but consequently induced apoptosis as evidenced by generating an apoptotic peak. The induction of apoptosis was confirmed by the results of DNA fragmentation assays and alterations in cell morphology after treatment of the cells with G-Rs4. Immunoblot assays showed that G-Rs4 significantly elevated protein levels of p53 and p21WAF1, concurrently with the downregulation of both cyclins E- and A-dependent kinase activities and induction of apoptosis. We suggest that G-Rs4 induces apoptosis, the effect of which is closely related to the downregulation of both cyclins E- and A-dependent kinase activity as a consequence of selectively elevating protein levels of p53 and p21WAF1 in SK-HEP-1 cells.
apoptosis, p53, ginsenoside-Rs4, p21WAF1, CDK2
Structure type: oligomerNew query | Export IDs | Home | Help |
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