Positive Modulation of IL-12 Signaling by Sphingosine Kinase 2 Associating with the IL-12 Receptor β1 Cytoplasmic Region

Yoshimoto, Takayuki; Furuhata, Masae; Kamiya, Sadahiro; Hisada, Masayuki; Miyaji, Hiroko; Magami, Yasushi; Yamamoto, Koh; Fujiwara, Hiromi; Mizuguchi, Junichiro

doi:10.4049/jimmunol.171.3.1352

Cited by 62 publications

(62 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, we found that mutation of the conserved leucine in the SphK2 BH3 domain did not abolish its localization to the ER, suggesting that its putative transmembrane domains might also contribute to its association with internal membranes. Alternatively, SphK2 may interact with other membrane proteins (37). Consistent with the notion that localization of SphK2 to the ER and internal membranes is important for its function, targeting cytosolic SphK1, but not catalytically inactive SphK1, to the ER converted it from anti-apoptotic to pro-apoptotic.…”

Section: Dihydro-sphsupporting

confidence: 53%

“…Igarashi and co-workers (27) reported that when SphK2 was transiently expressed in HeLa and COS7 cells, it was localized in the nuclei, whereas in HEK 293 cells it was localized to the cytosol. In contrast, overexpressed SphK2 was found to associate with the interleukin-12 receptor-␤1 at the plasma membrane in HEK 293 cells and T cell hybridomas (37). However, using a specific antibody, we …”

Section: Discussionmentioning

confidence: 82%

“…This suggests that SphK2 can be localized to the ER in BH3-dependent and independent manners. This is not so surprising as SphK2 also contains numerous putative transmembrane domains and has also been shown to interact with other membrane proteins, including the interleukin-12 receptor ␤1 (37).…”

Section: Apoptosis Induced By Sphk2mentioning

confidence: 99%

See 2 more Smart Citations

SphK1 and SphK2, Sphingosine Kinase Isoenzymes with Opposing Functions in Sphingolipid Metabolism

Maceyka

Sankala

Hait

et al. 2005

Journal of Biological Chemistry

573

549

View full text Add to dashboard Cite

The potent sphingolipid metabolite sphingosine 1-phosphate is produced by phosphorylation of sphingosine catalyzed by sphingosine kinase (SphK) types 1 and 2. In contrast to pro-survival SphK1, the putative BH3-only protein SphK2 inhibits cell growth and enhances apoptosis. Here we show that SphK2 catalytic activity also contributes to its ability to induce apoptosis. Overexpressed SphK2 also increased cytosolic free calcium induced by serum starvation. Transfer of calcium to mitochondria was required for SphK2-induced apoptosis, as cell death and cytochrome c release was abrogated by inhibition of the mitochondrial Ca 2؉ transporter. Serum starvation increased the proportion of SphK2 in the endoplasmic reticulum and targeting SphK1 to the endoplasmic reticulum converted it from anti-apoptotic to pro-apoptotic. Overexpression of SphK2 increased incorporation of [ 3 H]palmitate, a substrate for both serine palmitoyltransferase and ceramide synthase, into C16-ceramide, whereas SphK1 decreased it. Electrospray ionizationmass spectrometry/mass spectrometry also revealed an opposite effect on ceramide mass levels. Importantly, specific down-regulation of SphK2 reduced conversion of sphingosine to ceramide in the recycling pathway and conversely, down-regulation of SphK1 increased it. Our results demonstrate that SphK1 and SphK2 have opposing roles in the regulation of ceramide biosynthesis and suggest that the location of sphingosine 1-phosphate production dictates its functions.The sphingolipid metabolite, sphingosine 1-phosphate (S1P), 3 a ligand for a family of five specific G protein-coupled receptors, and regulates many important cellular processes including growth, survival, differentiation, cytoskeleton rearrangements, motility, angiogenesis, and immunity (reviewed in Refs. 1-3). Although there is no doubt that S1P acts extracellularly, several studies suggest that this potent lipid, like its precursors sphingosine (4) and ceramide (N-acylsphingosine) (5-7), may also have intracellular functions important for calcium homeostasis (8), cell growth (9, 10), and suppression of apoptosis (11)(12)(13)(14).Like other lipid mediators, S1P levels are tightly regulated by the balance between synthesis, catalyzed by sphingosine kinase (SphK), irreversible cleavage by S1P lyase, and reversible dephosphorylation to sphingosine by specific S1P phosphatases. Two distinct SphK isoforms, SphK1 and SphK2, have been cloned and characterized (15,16). Diverse external stimuli, particularly growth and survival factors, stimulate SphK1 and intracellularly generated S1P has been implicated in their mitogenic and anti-apoptotic effects (10,13,(17)(18)(19)(20)(21)(22)(23)(24). Expression of SphK1 enhanced proliferation and growth in soft agar, promoted the G 1 -S transition, protected cells from apoptosis (10,14,17), and induced tumor formation in mice (17, 18). However, although SphK1 and intracellularly generated S1P can signal "inside-out" to regulate cytoskeletal rearrangements and cell movement, remarkably, cell growth stimulation...

show abstract

Section: Dihydro-sphsupporting

confidence: 53%

Section: Discussionmentioning

confidence: 82%

See 1 more Smart Citation

SphK1 and SphK2, Sphingosine Kinase Isoenzymes with Opposing Functions in Sphingolipid Metabolism

Maceyka

Sankala

Hait

et al. 2005

Journal of Biological Chemistry

573

549

View full text Add to dashboard Cite

show abstract

“…Cells were lysed in a lysis buffer containing protease inhibitors, and resultant cell lysates were separated on an SDS-PAGE under reducing conditions and transferred to polyvinylidene difluoride membrane (Millipore) as described previously (31). The membrane was then blocked, probed with primary Ab and then with appropriate secondary Ab conjugated to HRP, and visualized with the ECL detection system (Amersham Biosciences) according to the manufacturer's instructions.…”

Section: Western Blottingmentioning

confidence: 99%

STAT3 Is Indispensable to IL-27-Mediated Cell Proliferation but Not to IL-27-Induced Th1 Differentiation and Suppression of Proinflammatory Cytokine Production

Owaki

Asakawa

Morishima

et al. 2008

The Journal of Immunology

Self Cite

View full text Add to dashboard Cite

IL-27, a member of the IL-6/IL-12 family, activates both STAT1 and STAT3 through its receptor, which consists of WSX-1 and gp130 subunits, resulting in augmentation of Th1 differentiation and suppression of proinflammatory cytokine production. In the present study, we investigated the role of STAT3 in the IL-27-mediated immune functions. IL-27 induced phosphorylation of STAT1, -2, -3 and -5 in wild-type naive CD4+ T cells, but failed to induce that of STAT3 and STAT5 in STAT3-deficient cohorts. IL-27 induced not only proinflammatory responses including up-regulation of ICAM-1, T-box expressed in T cells, and IL-12Rβ2 and Th1 differentiation, but also anti-inflammatory responses including suppression of proinflammatory cytokine production such as IL-2, IL-4, and IL-13 even in STAT3-deficient naive CD4+ T cells. In contrast, IL-27 augmented c-Myc and Pim-1 expression and induced cell proliferation in wild-type naive CD4+ T cells but not in STAT3-deficient cohorts. Moreover, IL-27 failed to activate STAT3, augment c-Myc and Pim-1 expression, and induce cell proliferation in pro-B BaF/3 transfectants expressing mutant gp130, in which the putative STAT3-binding four Tyr residues in the YXXQ motif of the cytoplasmic region was replaced by Phe. These results suggest that STAT3 is activated through gp130 by IL-27 and is indispensable to IL-27-mediated cell proliferation but not to IL-27-induced Th1 differentiation and suppression of proinflammatory cytokine production. Thus, IL-27 may be a cytokine, which activates both STAT1 and STAT3 through distinct receptor subunits, WSX-1 and gp130, respectively, to mediate its individual immune functions.

show abstract

“…The SphFl concentrations used were 2. 5,5,10,15,20,30,40, and 60 μM, using 2% fatty-acid free BSA as a carrier for SphFl. The K M and V max were determined assuming Michaelis-Menten kinetics and fitting the data points in Origin (OriginLab Corporation, Northampton, MA).…”

mentioning

confidence: 99%

Determination of Sphingosine Kinase Activity for Cellular Signaling Studies

et al. 2008

View full text Add to dashboard Cite

Regulation of sphingosine and sphingosine-1-phosphate concentrations is of growing interest due to their importance in cellular signal transduction. Furthermore, new pharmaceutical agents moderating the intracellular and extracellular levels of sphingosine metabolites are showing promise in preclinical and clinical trials. In the present work, a quantitative assay relying on capillary electrophoresis with laser-induced fluorescence detection was developed to measure the interconversion of sphingosine and sphingosine-1-phosphate. The assay was demonstrated to be capable of determining the in vitro activity of both kinase and phosphatase using purified enzymes. The K M of sphingosine kinase for its fluorescently labeled substrate was 38 ± 18 μM with a V max of 0.4 ± 0.2 μM/min and a k cat of 3900 s −1 . Pharmacologic inhibition of sphingosine kinase in a concentration-dependent manner was also demonstrated. Moreover, the fluorescent substrate was shown to be readily taken up by mammalian cells making it possible to study the endogenous activity of sphingosine kinase activity in living cells. The method was readily adaptable to the use of either bulk cell lysates or very small numbers of intact cells. This new methodology provides enhancements over standard methods in sensitivity, quantification, and manpower for both in vitro and cell-based assays.The sphingolipids sphingosine and sphingosine-1-phosphate (S1P) play crucial roles as signal transduction molecules involved in cell survival and migration. [1][2][3][4][5][6] These second messengers along with the sphingolipid metabolite ceramide are interconvertible, and their dynamic equilibrium is believed to be a determining factor in whether cells will live or die. 7 In addition to its role as an intracellular second messenger, S1P also acts as an extracellular ligand making it a pleiotropic signaling molecule with wide-ranging function from calcium homeostasis to chemotaxis. 4,[7][8][9] S1P is produced by phosphorylation of sphingosine by sphingosine kinase 1 and 2 (SK1 and SK2) and is reversibly dephosphorylated by two known mammalian phosphatases SPP1 and SPP2. 6,[9][10][11] In addition, S1P can be irreversibly degraded by a pyridoxylphosphate-dependent S1P lyase to hexadecenal and phosphoethanolamine. 6,12 The balance and interplay of these metabolic pathways remain to be fully elucidated. SK1 is thought to be oncogenic, and inhibitors of SK1 appear to act as effective chemotherapeutic agents in animal studies. 7,10,13,14 SK2 is involved in the immune response, and compounds directed at extracellular S1P signaling are showing great promise in clinical trials for autoimmune diseases. 10,[15][16][17][18] Thus, sphingosine signaling is proving to be extremely important in clinical medicine. [17][18][19][20][21] *Corresponding authors. Phone: 919-966-2291 (C.E.S. and N.L.A.). Fax: 919-962-2388 (C.E.S. and N.L.A.). cesims@unc.edu (C.E.S.); nlallbri@unc.edu (N.L.A. Although S1P plays a major role as an extracellular signaling molecule, it is predominately syn...

show abstract

Positive Modulation of IL-12 Signaling by Sphingosine Kinase 2 Associating with the IL-12 Receptor β1 Cytoplasmic Region

Cited by 62 publications

References 50 publications

SphK1 and SphK2, Sphingosine Kinase Isoenzymes with Opposing Functions in Sphingolipid Metabolism

SphK1 and SphK2, Sphingosine Kinase Isoenzymes with Opposing Functions in Sphingolipid Metabolism

STAT3 Is Indispensable to IL-27-Mediated Cell Proliferation but Not to IL-27-Induced Th1 Differentiation and Suppression of Proinflammatory Cytokine Production

Determination of Sphingosine Kinase Activity for Cellular Signaling Studies

Contact Info

Product

Resources

About