scholarly journals Sphingosine and Sphingosine Kinase 1 Involvement in Endocytic Membrane Trafficking

2017 ◽  
Vol 292 (8) ◽  
pp. 3074-3088 ◽  
Author(s):  
Santiago Lima ◽  
Sheldon Milstien ◽  
Sarah Spiegel
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Sphingosine Kinase ◽  
Cell Types ◽  
Membrane Cholesterol ◽  
Vesicle Formation ◽  
Sphingosine Kinase 1 ◽  
Late Endosomes ◽  
Sphingosine 1 Phosphate ◽  
Plasma Membrane Cholesterol

The balance between cholesterol and sphingolipids within the plasma membrane has long been implicated in endocytic membrane trafficking. However, in contrast to cholesterol functions, little is still known about the roles of sphingolipids and their metabolites. Perturbing the cholesterol/sphingomyelin balance was shown to induce narrow tubular plasma membrane invaginations enriched with sphingosine kinase 1 (SphK1), the enzyme that converts the bioactive sphingolipid metabolite sphingosine to sphingosine-1-phosphate, and suggested a role for sphingosine phosphorylation in endocytic membrane trafficking. Here we show that sphingosine and sphingosine-like SphK1 inhibitors induced rapid and massive formation of vesicles in diverse cell types that accumulated as dilated late endosomes. However, much smaller vesicles were formed in SphK1-deficient cells. Moreover, inhibition or deletion of SphK1 prolonged the lifetime of sphingosine-induced vesicles. Perturbing the plasma membrane cholesterol/sphingomyelin balance abrogated vesicle formation. This massive endosomal influx was accompanied by dramatic recruitment of the intracellular SphK1 and Bin/Amphiphysin/Rvs domain-containing proteins endophilin-A2 and endophilin-B1 to enlarged endosomes and formation of highly dynamic filamentous networks containing endophilin-B1 and SphK1. Together, our results highlight the importance of sphingosine and its conversion to sphingosine-1-phosphate by SphK1 in endocytic membrane trafficking.

scholarly journals Phospholipase C and Protein Kinase C-β 2 Mediate Insulin-Like Growth Factor II-Dependent Sphingosine Kinase 1 Activation

2011 ◽  
Vol 25 (12) ◽  
pp. 2144-2156 ◽  
Author(s):  
Hesham M. El-Shewy ◽  
Souzan A. Abdel-Samie ◽  
Abdelmohsen M. Al Qalam ◽  
Mi-Hye Lee ◽  
Kazuyuki Kitatani ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Fluorescent Protein ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Membrane Translocation ◽  
Kinase C ◽  
Sphingosine 1 Phosphate

Abstract We recently reported that IGF-II binding to the IGF-II/mannose-6-phosphate (M6P) receptor activates the ERK1/2 cascade by triggering sphingosine kinase 1 (SK1)-dependent transactivation of G protein-coupled sphingosine 1-phosphate (S1P) receptors. Here, we investigated the mechanism of IGF-II/M6P receptor-dependent sphingosine kinase 1 (SK1) activation in human embryonic kidney 293 cells. Pretreating cells with protein kinase C (PKC) inhibitor, bisindolylmaleimide-I, abolished IGF-II-stimulated translocation of green fluorescent protein (GFP)-tagged SK1 to the plasma membrane and activation of endogenous SK1, implicating PKC as an upstream regulator of SK1. Using confocal microscopy to examine membrane translocation of GFP-tagged PKCα, β1, β2, δ, and ζ, we found that IGF-II induced rapid, transient, and isoform-specific translocation of GFP-PKCβ2 to the plasma membrane. Immunoblotting of endogenous PKC phosphorylation confirmed PKCβ2 activation in response to IGF-II. Similarly, IGF-II stimulation caused persistent membrane translocation of the kinase-deficient GFP-PKCβ2 (K371R) mutant, which does not dissociate from the membrane after translocation. IGF-II stimulation increased diacylglycerol (DAG) levels, the established activator of classical PKC. Interestingly, the polyunsaturated fraction of DAG was increased, indicating involvement of phosphatidyl inositol/phospholipase C (PLC). Pretreating cells with the PLC inhibitor, U73122, attenuated IGF-II-dependent DAG production and PKCβ2 phosphorylation, blocked membrane translocation of the kinase-deficient GFP-PKCβ2 (K371R) mutant, and reduced sphingosine 1-phosphate production, suggesting that PLC/PKCβ2 are upstream regulators of SK1 in the pathway. Taken together, these data provide evidence that activation of PLC and PKCβ2 by the IGF-II/M6P receptor are required for the activation of SK1.

scholarly journals Monoclonal antibody detection of plasma membrane cholesterol microdomains responsive to cholesterol trafficking

2001 ◽  
Vol 42 (9) ◽  
pp. 1492-1500 ◽  
Author(s):  
Howard S. Kruth ◽  
Ina Ifrim ◽  
Janet Chang ◽  
Lia Addadi ◽  
Daniele Perl-Treves ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Plasma Membrane ◽  
Antibody Detection ◽  
Membrane Cholesterol ◽  
Cholesterol Trafficking ◽  
Plasma Membrane Cholesterol

Cell culturing in a three-dimensional matrix affects the localization and properties of plasma membrane cholesterol

2009 ◽  
Vol 33 (10) ◽  
pp. 1079-1086 ◽  
Author(s):  
Nadezhda Stefanova ◽  
Galya Staneva ◽  
Diana Petkova ◽  
Teodora Lupanova ◽  
Roumen Pankov ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Three Dimensional ◽  
Membrane Cholesterol ◽  
Dimensional Matrix ◽  
Cell Culturing ◽  
Plasma Membrane Cholesterol

scholarly journals Mice Deficient in Sphingosine Kinase 1 Are Rendered Lymphopenic by FTY720

2004 ◽  
Vol 279 (50) ◽  
pp. 52487-52492 ◽  
Author(s):  
Maria L. Allende ◽  
Teiji Sasaki ◽  
Hiromichi Kawai ◽  
Ana Olivera ◽  
Yide Mi ◽  
...  
Keyword(s):  
Vascular Development ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Cellular Functions ◽  
Lymphocyte Trafficking ◽  
Signaling Molecule ◽  
Physiological Functions ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
S1p Receptor

Sphingosine-1-phosphate (S1P), a lipid signaling molecule that regulates many cellular functions, is synthesized from sphingosine and ATP by the action of sphingosine kinase. Two such kinases have been identified, SPHK1 and SPHK2. To begin to investigate the physiological functions of sphingosine kinase and S1P signaling, we generated mice deficient in SPHK1.Sphk1null mice were viable, fertile, and without any obvious abnormalities. Total SPHK activity in mostSphk1-/-tissues was substantially, but not completely, reduced indicating the presence of multiple sphingosine kinases. S1P levels in most tissues from theSphk1-/- mice were not markedly decreased. In serum, however, there was a significant decrease in the S1P level. Although S1P signaling regulates lymphocyte trafficking, lymphocyte distribution was unaffected in lymphoid organs ofSphk1-/- mice. The immunosuppressant FTY720 was phosphorylated and elicited lymphopenia in theSphk1null mice showing that SPHK1 is not required for the functional activation of this sphingosine analogue prodrug. The results with theseSphk1null mice reveal that some key physiologic processes that require S1P receptor signaling, such as vascular development and proper lymphocyte distribution, can occur in the absence of SPHK1.

scholarly journals Sphingosine 1-phosphate in inflammation

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Lijuan Li ◽  
Lixia An ◽  
Lifang Li ◽  
Yongjuan Zhao
Keyword(s):  
Plasma Membrane ◽  
Drug Targets ◽  
Therapeutic Potential ◽  
Cell Types ◽  
In Vivo Models ◽  
Integral Role ◽  
Sphingosine 1 Phosphate ◽  
And Migration

Sphingolipids are formed via the metabolism of sphingomyelin, aconstituent of the plasma membrane, or by denovosynthesis. Enzymatic pathways result in the formation of several different lipid mediators, which are known to have important roles in many cellular processes, including proliferation, apoptosis and migration. Several studies now suggest that these sphingolipid mediators, including ceramide, ceramide 1-phosphate and sphingosine 1-phosphate (S1P), are likely to have an integral role in in?ammation. This can involve, for example, activation of pro-in?ammatory transcription factors in different cell types and induction of cyclooxygenase-2, leading to production of pro-in?ammatory prostaglandins. The mode of action of each sphingolipid is different. Increased ceramide production leads to the formation of ceramide-rich areas of the membrane, which may assemble signalling complexes, whereas S1P acts via high-af?nity G-protein-coupled S1P receptors on the plasma membrane. Recent studies have demonstrated that in vitro effects of sphingolipids on in?ammation can translate into in vivo models. This review will highlight the areas of research where sphingolipids are involved in in?ammation and the mechanisms of action of each mediator. In addition, the therapeutic potential of drugs that alter sphingolipid actions will be examined with reference to disease states, such as asthma and in?ammatory bowel disease, which involve important in?ammatory components. A signi?cant body of research now indicates that sphingolipids are intimately involved in the in?ammatory process and recent studies have demonstrated that these lipids, together with associated enzymes and receptors, can provide effective drug targets for the treatment of pathological in?ammation.

Sign in / Sign up

Export Citation Format

Share Document