Reaction participants Show >> << Hide
- Name help_outline a sphingoid base Identifier CHEBI:84410 Charge 1 Formula C3H9NO2R SMILEShelp_outline [NH3+][C@@H](CO)[C@H](O)[*] 2D coordinates Mol file for the small molecule Search links Involved in 137 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline hexadecanoyl-CoA Identifier CHEBI:57379 Charge -4 Formula C37H62N7O17P3S InChIKeyhelp_outline MNBKLUUYKPBKDU-BBECNAHFSA-J SMILEShelp_outline [C@@H]1(N2C3=C(C(=NC=N3)N)N=C2)O[C@H](COP(OP(OCC(C)([C@H](C(NCCC(NCCSC(CCCCCCCCCCCCCCC)=O)=O)=O)O)C)(=O)[O-])(=O)[O-])[C@H]([C@H]1O)OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 110 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline an N-hexadecanoyl-sphingoid base Identifier CHEBI:144703 Charge 0 Formula C19H38NO3R SMILEShelp_outline OC[C@@H]([C@@H](*)O)NC(=O)CCCCCCCCCCCCCCC 2D coordinates Mol file for the small molecule Search links Involved in 21 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline CoA Identifier CHEBI:57287 (Beilstein: 11604429) help_outline Charge -4 Formula C21H32N7O16P3S InChIKeyhelp_outline RGJOEKWQDUBAIZ-IBOSZNHHSA-J SMILEShelp_outline CC(C)(COP([O-])(=O)OP([O-])(=O)OC[C@H]1O[C@H]([C@H](O)[C@@H]1OP([O-])([O-])=O)n1cnc2c(N)ncnc12)[C@@H](O)C(=O)NCCC(=O)NCCS 2D coordinates Mol file for the small molecule Search links Involved in 1,500 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:61472 | RHEA:61473 | RHEA:61474 | RHEA:61475 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Related reactions help_outline
Specific form(s) of this reaction
More general form(s) of this reaction
Publications
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LASS5 is a bona fide dihydroceramide synthase that selectively utilizes palmitoyl-CoA as acyl donor.
Lahiri S., Futerman A.H.
We demonstrated recently (Riebeling, C., Allegood, J.C., Wang, E., Merrill, A. H. Jr., and Futerman, A. H. (2003) J. Biol. Chem. 278, 43452-43459) that upon over-expression in human embryonic kidney cells, longevity assurance gene homolog 5 (LASS5, previously named TRH4) elevates the synthesis of ... >> More
We demonstrated recently (Riebeling, C., Allegood, J.C., Wang, E., Merrill, A. H. Jr., and Futerman, A. H. (2003) J. Biol. Chem. 278, 43452-43459) that upon over-expression in human embryonic kidney cells, longevity assurance gene homolog 5 (LASS5, previously named TRH4) elevates the synthesis of (dihydro)ceramides selectively enriched in palmitic acid. To determine whether LASS5 is a bona fide dihydroceramide synthase or, alternatively, whether it modifies an endogenous dihydroceramide synthase, we over-expressed LASS5 with a hemagglutinin (HA) tag at the C terminus, solubilized it using digitonin, and purified it by immunoprecipitation. Solubilized LASS5-HA displays the same fatty acid selectivity as the membrane-bound enzyme. After elution from agarose beads, only one band could be detected by SDS-PAGE, and its identity was confirmed to be LASS5 by mass spectrometry. Dihydroceramide synthase activity of the eluted LASS5-HA protein was totally dependent on exogenously added phospholipids. Moreover, eluted LASS5-HA was highly selective toward palmitoyl-CoA as acyl donor and was inhibited by the (dihydro)ceramide synthase inhibitor, fumonisin B1. This study identifies LASS5 as a genuine dihydroceramide synthase and demonstrates that mammalian dihydroceramide synthases do not require additional subunits for their activity. << Less
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LASS5 is the predominant ceramide synthase isoform involved in de novo sphingolipid synthesis in lung epithelia.
Xu Z., Zhou J., McCoy D.M., Mallampalli R.K.
Ceramide is a key bioactive mediator that inhibits surfactant phosphatidylcholine (PtdCho) synthesis in lung epithelia. Ceramide availability is governed by sphingomyelin (SM) hydrolysis, but less is known regarding its de novo synthesis. In this study, we observed that ceramide synthesis within m ... >> More
Ceramide is a key bioactive mediator that inhibits surfactant phosphatidylcholine (PtdCho) synthesis in lung epithelia. Ceramide availability is governed by sphingomyelin (SM) hydrolysis, but less is known regarding its de novo synthesis. In this study, we observed that ceramide synthesis within murine lung epithelia was associated with high-level ceramide synthase (dihydroceramide synthase) activity. Longevity assurance homolog 5 (LASS5) was the predominant ceramide synthase isoform detected in lung epithelia, whereas relatively lower level expression was detected for the other five mammalian homologs. Pulmonary LASS5 was developmentally regulated, but its expression was spatially and gender nonspecific. Exogenously expressed LASS5 in lung epithelia was membrane-associated, triggering increased ceramide synthesis, whereas knockdown studies using fumonisin B1 or LASS5 small, interfering RNA reduced ceramide synthase activity by 78% or 45%, respectively. Overexpression of LASS5 also reduced PtdCho synthesis, but maximal inhibition was achieved when LASS5 was coexpressed with a plasmid encoding a neutral sphingomyelinase involved in SM hydrolysis. These results demonstrate that LASS5 is the major ceramide synthase gene product involved in sphingolipid production that may also regulate PtdCho metabolism in pulmonary epithelia. << Less
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Mammalian Lass6 and its related family members regulate synthesis of specific ceramides.
Mizutani Y., Kihara A., Igarashi Y.
The Lass (longevity-assurance homologue) family members, which are highly conserved among eukaryotes, function in ceramide synthesis. In the mouse, there are at least five Lass family members, Lass1, Lass2, Lass4, Lass5 and the hitherto uncharacterized Lass6. To investigate specific roles for each ... >> More
The Lass (longevity-assurance homologue) family members, which are highly conserved among eukaryotes, function in ceramide synthesis. In the mouse, there are at least five Lass family members, Lass1, Lass2, Lass4, Lass5 and the hitherto uncharacterized Lass6. To investigate specific roles for each Lass member in ceramide synthesis, we cloned these five mouse proteins. Overproduction of any Lass protein in cultured cells resulted in an increase in cellular ceramide, but the ceramide species produced varied. Overproduction of Lass1 increased C18:0-ceramide levels preferentially, and overproduction of Lass2 and Lass4 increased levels of longer ceramides such as C22:0- and C24:0-ceramides. Lass5 and Lass6 produced shorter ceramide species (C14:0- and C16:0-ceramides); however, their substrate preferences towards saturated/unsaturated fatty acyl-CoA differed. In addition to differences in substrate preferences, we also demonstrated by Northern blotting that Lass family members are differentially expressed among tissues. Additionally, we found that Lass proteins differ with regard to glycosylation. Of the five members, only Lass2, Lass5 and Lass6 were N-glycosylated, each at their N-terminal Asn residue. The occurrence of N-glycosylation of some Lass proteins provides topological insight, indicating that the N-termini of Lass family members probably face the luminal side of the endoplasmic reticulum membrane. Furthermore, based on a proteinase K digestion assay, we demonstrated that the C-terminus of Lass6 faces the cytosolic side of the membrane. From these data we propose topology for the conserved Lag1 motif in Lass family members, namely that the N-terminal region faces the luminal side and the C-terminal region the cytosolic side of the endoplasmic reticulum membrane. << Less
Biochem. J. 390:263-271(2005) [PubMed] [EuropePMC]
This publication is cited by 7 other entries.