Arabidopsis mutants lacking long chain base phosphate lyase are fumonisin-sensitive and accumulate trihydroxy-18:1 long chain base phosphate

Yoseph Tsegaye, Christopher G. Richardson, Janis E. Bravo, Brendan J. Mulcahy, Daniel V. Lynch, Jonathan E. Markham, Jan G. Jaworski, Ming Chen, Edgar B. Cahoon, Teresa M. Dunn

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


The sphingoid long chain bases (LCBs) and their phosphorylated derivatives (LCB-Ps) are important signaling molecules in eukaryotic organisms. The cellular levels of LCB-Ps are tightly controlled by the coordinated action of the LCB kinase activity responsible for their synthesis and the LCB-P phosphatase and lyase activities responsible for their catabolism. Although recent studies have implicated LCB-Ps as regulatory molecules in plants, in comparison with yeast and mammals, much less is known about their metabolism and function in plants. To investigate the functions of LCB-Ps in plants, we have undertaken the identification and characterization of Arabidopsis genes that encode the enzymes of LCB-P metabolism. In this study the Arabidopsis At1g27980 gene was shown to encode the only detectable LCB-P lyase activity in Arabidopsis. The LCB-P lyase activity was characterized, and mutant plant lines lacking the lyase were generated and analyzed. Whereas in other organisms loss of LCB-P lyase activity is associated with accumulation of high levels of LCB/LCB-Ps and developmental abnormalities, the sphingolipid profiles of the mutant plants were remarkably similar to those of wild-type plants, and no developmental abnormalities were observed. Thus, these studies indicate that the lyase plays a minor role in maintenance of sphingolipid metabolism during normal plant development and growth. However, a clear role for the lyase was revealed upon perturbation of sphingolipid synthesis by treatment with the inhibitor of ceramide synthase, fumonisin B1.

Original languageEnglish (US)
Pages (from-to)28195-28206
Number of pages12
JournalJournal of Biological Chemistry
Issue number38
StatePublished - Sep 21 2007
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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