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B6db references: 15522238

type Journal Article
authors Ikeda, M.; Kihara, A.; Igarashi, Y.
title Sphingosine-1-phosphate lyase SPL is an endoplasmic reticulum-resident, integral membrane protein with the pyridoxal 5'-phosphate binding domain exposed to the cytosol
journal Biochem Biophys Res Commun
sel unselected
ui 15522238
year (2004)
volume 325
number 1
pages 338-43.
keywords Aldehyde-Lyases/*chemistry/genetics
abstract Biochem Biophys Res Commun. 2004 Dec 3;325(1):338-43. Sphingosine-1-phosphate (S1P) is a sphingolipid metabolite that functions as a bioactive lipid molecule. S1P is degraded either by S1P lyase or by S1P phosphohydrolase. The gene encoding mammalian S1P lyase, SPL, has been identified. Here, we characterize the SPL protein in its expression, localization, and topology. The expression levels of the SPL protein correlated well with the dihydrosphingosine-1-phosphate (DHS1P) lyase activity in most tissues. However, liver and heart exhibited high DHS1P lyase activities compared to their SPL protein levels. The SPL mRNA expression was temporally regulated during mouse embryonal development. Immunofluorescence microscopy demonstrated that SPL is localized at the endoplasmic reticulum. Proteinase K digestion studies revealed that the large hydrophilic domain, containing the active site, faces the cytosol. This active site orientation is opposite to that of S1P phosphohydrolase, indicating that the degradation of S1P by two S1P-degrading enzymes occurs in spatially separated sides of the endoplasmic reticulum.
last changed 2004/11/04 09:46

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