Sphingosine-1-phosphate phosphohydrolase regulates endoplasmic reticulum-to-golgi trafficking of ceramide.
Previous studies demonstrated that sphingosine-1-phosphate (S1P) phosphohydrolase 1 (SPP-1), which is located mainly in the endoplasmic reticulum (ER), regulates sphingolipid metabolism and apoptosis (H. Le Stunff et al., J. Cell Biol. 158:1039-1049, 2002). We show here that the treatment of SPP-1-overexpressing cells with S1P, but not with dihydro-S1P, increased all ceramide species, particularly the long-chain ceramides. This was not due to inhibition of ceramide metabolism to sphingomyelin or monohexosylceramides but rather to the inhibition of ER-to-Golgi trafficking, determined with the fluorescent ceramide analog N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-d-erythro-sphingosine (DMB-Cer). Fumonisin B1, an inhibitor of ceramide synthase, prevented S1P-induced elevation of all ceramide species and corrected the defect in ER transport of DMB-Cer, readily allowing its detection in the Golgi. In contrast, ceramide accumulation had no effect on either the trafficking or the metabolism of 6-([N-(7-nitrobenzo-2-oxa-1,3-diazol-4-yl)amino]hexanoyl)-sphingosine, which rapidly labels the Golgi even at 4 degrees C. Protein trafficking from the ER to the Golgi, determined with vesicular stomatitis virus ts045 G protein fused to green fluorescent protein, was also inhibited in SPP-1-overexpressing cells in the presence of S1P but not in the presence of dihydro-S1P. Our results suggest that SPP-1 regulates ceramide levels in the ER and thus influences the anterograde membrane transport of both ceramide and proteins from the ER to the Golgi apparatus.
Giussani
Paola
P
Department of Biochemistry, Virginia Commonwealth University School of Medicine, 1101 E. Marshall Street, Room 2-011 Sanger Hall, Richmond, VA 23298-0614, USA.
Maceyka
Michael
M
Le Stunff
Hervé
H
Mikami
Aki
A
Lépine
Sandrine
S
Wang
Elaine
E
Kelly
Samuel
S
Merrill
Alfred H
AH
Milstien
Sheldon
S
Spiegel
Sarah
S
D001692:Biological Transport / Q000187:drug effects; D001896:Boron Compounds / Q000032:analysis / Q000378:metabolism; D002478:Cells, Cultured; D002518:Ceramides / Q000032:analysis / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism*; D037341:Fumonisins / Q000494:pharmacology; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006056:Golgi Apparatus / Q000201:enzymology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism
D001896:Boron Compounds; D002518:Ceramides; D037341:Fumonisins; C028391:G protein, vesicular stomatitis virus; D008246:Lysophospholipids; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C405489:N-(4,4-difluoro-5,7-dimethyl-4--bora-3a,4a-diaza-s-indacene-3-pentanoyl)sphingosine; D014759:Viral Envelope Proteins; D049452:Green Fluorescent Proteins; C060506:sphingosine 1-phosphate; C056933:fumonisin B1; D010088:Oxidoreductases; C108138:dihydroceramide desaturase; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase; C401298:sphingosine-1-phosphate phosphatase; D010744:Phosphoric Monoester Hydrolases; D013110:Sphingosine