Characterization of sphingosine kinase (SK) activity in Saccharomyces cerevisiae and isolation of SK-deficient mutants - PubMed (original) (raw)

Characterization of sphingosine kinase (SK) activity in Saccharomyces cerevisiae and isolation of SK-deficient mutants

M M Lanterman et al. Biochem J. 1998.

Abstract

Sphingosine kinase (SK) catalyses the phosphorylation of sphingosine to generate sphingosine 1-phosphate, which is a second messenger involved in the proliferative responses of mammalian cells. Although the yeast Saccharomyces cerevisiae has similar phosphorylated sphingoid bases which appear to be involved in growth regulation and the response to stress, SK activity had not been previously demonstrated in yeast. In this study, an in vitro system was set up to characterize yeast SK activity. Activity was detected in the cytosol at neutral pH and 37 degreesC. Yeast SK phosphorylated the sphingoid bases sphingosine, dihydrosphingosine and phytosphingosine. (d,l)-threo-dihydrosphingosine, an inhibitor of mammalian SK, did not inhibit the yeast enzyme. Unique properties of yeast SK were an optimal temperature of 43 degreesC, and in vivo activation during nutrient deprivation. Spontaneous mutants with diminished SK activity were isolated utilizing a screen for resistance to sphingosine in a sphingosine-phosphate-lyase deletion background. Abnormal growth and heat sensitivity were observed in these mutants. These findings suggest that SK may function as a stress-response protein in yeast.

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References

    1. Biochim Biophys Acta. 1969 Mar 4;176(2):348-56 - PubMed
    1. Proc Natl Acad Sci U S A. 1998 Jan 6;95(1):150-5 - PubMed
    1. J Biol Chem. 1976 Aug 10;251(15):4557-64 - PubMed
    1. Anal Biochem. 1988 Jun;171(2):373-81 - PubMed
    1. Genetics. 1988 Sep;120(1):95-108 - PubMed

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