Characterization of sphingolipid long-chain base kinase in Arabidopsis thaliana.
Sphingolipid long-chain base (LCB) kinase catalyses the phosphorylation of sphingolipid LCB to form LCB 1-phosphate. Based on sequence identity to a murine sphingosine kinase (murine SPHK1a), we isolated and characterized a LCB kinase-like cDNA in Arabidopsis thaliana. The deduced amino acid sequence of the homologous cDNA shows several regions that are highly conserved in LCB kinases from mouse, yeast, human and Caenorhabditis elegans. These regions are not similar to those of other known kinase families. For a functional identification, the homologous cDNA from A. thaliana was expressed in Escherichia coli, and LCB kinase activity was measured. The recombinant AtLcbk1 protein was found to utilize ATP and sphinganine. These results indicate the first identification of a gene coding for a LCB kinase in plants.
Nishiura
H
H
Department of Biology, Faculty of Science, Konan University, Kobe 658-8501, Japan.
Tamura
K
K
Morimoto
Y
Y
Imai
H
H
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004926:Escherichia coli; D016366:Open Reading Frames; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D018076:DNA, Complementary; D011994:Recombinant Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C426837:sphingolipid long-chain base kinase