Identification of a sphingolipid‐specific phospholipase D activity associated with the generation of phytoceramide‐1‐phosphate in cabbage leaves. (5th July 2013)

• Record Type: Journal Article
• Authors: Tanaka, Tamotsu; Kida, Takashi; Imai, Hiroyuki; Morishige, Jun‐ichi; Yamashita, Ryouhei; Matsuoka, Hisatsugu; Uozumi, Sachika; Satouchi, Kiyoshi; Nagano, Minoru; Tokumura, Akira
• Is Part Of: FEBS journal. Volume 280:Number 16(2013)
• Page Start: 3797
• Page End: 3809
• Publication Date: 2013-07-05
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.12374
• Languages: English
• ISSNs: 1742-464X

Abstract

<abstract abstract-type="main" id="febs12374-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The structure and biosynthetic route for an unidentified lipid (lipid X) detected by TLC of cabbage (<italic>Brassica oleracea</italic>) lipids was determined. Lipid X is a phospholipid that is resistant to mild alkali and detectable by MALDI‐TOF MS as an adduct with Phos‐tag, a phosphate‐capture zinc complex. Various α‐hydroxy fatty acids (16:0, 22:0, 24:0 and 24:1) were detected by GC‐MS of fatty acid methyl esters prepared from lipid X. The deacyl derivative of lipid X was determined to be 4‐hydroxysphingenine (dehydrophytosphingosine)‐1‐phosphate by MALDI‐TOF MS with Phos‐tag. From these results, lipid X was determined to be phytoceramide‐1‐phosphate (PC1P) with an α‐hydroxy fatty acid. When cabbage homogenates were incubated, PC1P was formed, with a concomitant decrease in the amount of glycosylinositol phosphoceramide (GIPC). The formation of PC1P from GIPC was confirmed by treatment of purified cabbage GIPC with a membrane fraction of cabbage homogenates. Using a partially purified enzyme fraction, we found that the enzyme hydrolyzes GIPC specifically, but not glycerophospholipids and sphingomyelin. <italic>Arabidopsis thaliana</italic> also had this enzyme activity. From these results, we conclude that a previously uncharacterized phospholipase D activity that specifically hydrolyzes GIPC produces PC1P in brassicaceous plants.</p> </abstract>