Sphingosine interaction with acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) regulates PP2A activity and cyclooxygenase (COX)-2 expression in human endothelial cells Journal Article

   

Authors:	Habrukowich, C.; Han, D. K.; Le, A.; Rezaul, K.; Pan, W.; Ghosh, M.; Li, Z.; Dodge-Kafka, K.; Jiang, X.; Bittman, R.; Hla, T.
Article Title:	Sphingosine interaction with acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) regulates PP2A activity and cyclooxygenase (COX)-2 expression in human endothelial cells
Abstract:	Sphingolipid metabolites regulate cell fate by acting on specific cellular targets. Although the influence of sphingolipids in cellular signaling has been well recognized, the exact molecular targets and how these targets influence cellular signaling mechanisms remain poorly understood. Toward this goal, we used affinity chromatography coupled with proteomics technology and identified acidic leucine-rich nuclear phosphoprotein-32A (ANP32A), an inhibitor of protein phosphatase 2A (PP2A) as a direct target of sphingosine, N,N'-dimethyl sphingosine (DMS) and phytosphingosine but not dihydrosphingosine or sphingosine 1-phosphate. Treatment of human umbilical vein endothelial cells (HUVEC) with DMS, which is not phosphorylated by sphingosine kinases, led to the activation of PP2A activity. Suppression of ANP32A with siRNA enhanced basal and DMS-activated PP2A activity suggesting that the sphingoid base binds to and relieves the inhibitory action of ANP32A on the PP2A complex. Indeed, DMS relieved the ANP32A-mediated inhibition of PP2A enzyme complex in vitro. Interestingly, DMS treatment induced the p38 stress-activated protein kinase (SAPK) and expression of cyclooxygenase (COX)-2 transcript and protein. Knockdown of ANP32A expression further induced p38 SAPK and COX-2. These data identify ANP32A as a novel molecular target of sphingoid bases that regulates cellular signaling events and inflammatory gene expression. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.
Keywords:	signal transduction; controlled study; protein expression; protein phosphorylation; unclassified drug; human cell; proteins; complex formation; enzyme inhibition; gene expression; signaling; mitogen activated protein kinase p38; protein protein interaction; protein targeting; cell line; rna, small interfering; enzyme activation; in vitro study; enzyme activity; phosphorylation; proteomics; endothelium cell; endothelial cells; rna; gene expression regulation; enzyme regulation; umbilical vein; enzyme inhibitors; intracellular signaling peptides and proteins; cyclooxygenase 2; real time polymerase chain reaction; amino acids; molecular biology; sphinganine; sphingolipids; sphingosine; in-vitro; phosphoprotein; protein synthesis inhibition; cellular signaling; gene expression regulation, enzymologic; cell fates; protein phosphatase 2a; self assembly; phosphoprotein phosphatase 2a; protein phosphatase 2; cellular targets; cyclooxygenases; enzyme complexes; human endothelial cells; human umbilical vein endothelial cells; inflammatory genes; molecular targets; phytosphingosines; proteomics technology; sphingoid basis; sphingosine 1 phosphates; sphingosine kinase; stress-activated protein kinase; affinity chromatography; diamonds; molecular physics; acidic leucine rich nuclear phosphoprotein 32a; n,n dimethylsphingosine; phytosphingosine; map kinase kinase 4; sphingoidea
Journal Title:	Journal of Biological Chemistry
Volume:	285
Issue:	35
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Date Published:	2010-08-27
Start Page:	26825
End Page:	26831
Language:	English
DOI:	10.1074/jbc.M110.147058
PUBMED:	20558741
PROVIDER:	scopus
PMCID:	PMC2930681
DOI/URL:	http://www.scopus.com/inward/record.url?eid=2-s2.0-77956259768&partnerID=40&md5=6c89323eaa4fc2b89ed80845e60e7196
Notes:	--- - "Cited By (since 1996): 1" - "Export Date: 20 April 2011" - "CODEN: JBCHA" - "Source: Scopus"

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