title: Neutral sphingomyelinase 2 activity and protein stability are modulated by phosphorylation of five conserved serines.
abstract: We previously presented that the neutral sphingomyelinase 2 (nSMase2) is the only SMase activated in human airway epithelial (HAE) cells following exposure to oxidative stress (ox-stress), yielding ceramide accumulation and thereby inducing apoptosis. Furthermore, we reported that nSMase2 is a phospho-protein in which the level of phosphorylation controls nSMase2 activation induced by ox-stress. Here we identify five specific serines that are phosphorylated in nSMase2 and demonstrate that their phosphorylation controls the nSMase2 activity upon ox-stress exposure in an interdependent manner. Furthermore, we show that the nSMase2 protein stability and thus its level of expression is also post-translationally regulated by these five serine phosphorylation sites. This study provides initial structure/function insights regarding nSMase2 phosphorylation sites and offers some new links for future studies aiming to fully elucidate nSMase2 regulatory machinery.
authors.affiliation: Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California School of Medicine, Davis, California 95616.
authors.forename: Simone
authors.initials: S
authors.lastname: Filosto
authors.affiliation: Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California School of Medicine, Davis, California 95616.
authors.forename: Majid
authors.initials: M
authors.lastname: Ashfaq
authors.affiliation: Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California School of Medicine, Davis, California 95616.
authors.forename: Samuel
authors.initials: S
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California School of Medicine, Davis, California 95616.
authors.forename: William
authors.initials: W
authors.lastname: Fry
authors.affiliation: Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California School of Medicine, Davis, California 95616. Electronic address: ttgoldkorn@ucdavis.edu.
authors.forename: Tzipora
authors.initials: T
authors.lastname: Goldkorn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D045744:Cell Line, Tumor; D017124:Conserved Sequence; D004795:Enzyme Stability; D004847:Epithelial Cells / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D013108:Sphingomyelin Phosphodiesterase / Q000737:chemistry* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D010768:Phosphoserine; C491483:Smpd3 protein, mouse; D013108:Sphingomyelin Phosphodiesterase
references.citation: J Biol Chem. 2007 Jan 12;282(2):1384-96
references.pmid: 17085432
references.citation: Lipids. 1999;34 Suppl:S5-11
references.pmid: 10419081
references.citation: Subcell Biochem. 2008;49:469-86
references.pmid: 18751923
references.citation: Neuroscience. 2005;130(3):657-66
references.pmid: 15590150
references.citation: Am J Respir Cell Mol Biol. 2000 Apr;22(4):460-8
references.pmid: 10745027
references.citation: Biochemistry. 2006 Sep 26;45(38):11247-56
references.pmid: 16981685
references.citation: Science. 2011 Jun 10;332(6035):1317-22
references.pmid: 21659604
references.citation: Am J Respir Crit Care Med. 2008 Dec 1;178(11):1100-14
references.pmid: 18755926
references.citation: Biochem Cell Biol. 2004 Feb;82(1):27-44
references.pmid: 15052326
references.citation: Hepatology. 2007 Oct;46(4):1166-76
references.pmid: 17668873
references.citation: J Biol Chem. 1994 Feb 11;269(6):4070-7
references.pmid: 8307965
references.citation: Am J Respir Cell Mol Biol. 2011 Mar;44(3):350-60
references.pmid: 20448054
references.citation: J Biol Chem. 1998 Feb 27;273(9):5053-9
references.pmid: 9478955
references.citation: J Lipid Res. 2007 Nov;48(11):2443-52
references.pmid: 17693623
references.citation: Am J Physiol Lung Cell Mol Physiol. 2009 Jul;297(1):L125-33
references.pmid: 19395669
references.citation: Adv Enzyme Regul. 2011;51(1):51-8
references.pmid: 21035485
references.citation: Neuromolecular Med. 2010 Dec;12(4):320-30
references.pmid: 20552297
references.citation: J Biol Chem. 2010 Apr 2;285(14):10213-22
references.pmid: 20106976
references.citation: Cell. 2010 Dec 23;143(7):1174-89
references.pmid: 21183079
references.citation: J Biol Chem. 2004 Jun 11;279(24):25101-11
references.pmid: 15051724
references.citation: Am J Respir Cell Mol Biol. 2001 Oct;25(4):409-17
references.pmid: 11694445
references.citation: Am J Respir Cell Mol Biol. 2010 Sep;43(3):259-68
references.pmid: 20525802
references.citation: Mol Pharmacol. 2008 Oct;74(4):1022-32
references.pmid: 18653803
references.citation: J Lipid Res. 2009 Apr;50 Suppl:S91-6
references.pmid: 19017611
references.citation: Trends Biochem Sci. 1999 Jun;24(6):224-5; author reply 227
references.pmid: 10366847
references.citation: Biochem Biophys Res Commun. 2006 Jun 9;344(3):900-5
references.pmid: 16631623
references.citation: Biochim Biophys Acta. 2010 Dec;1801(12):1361-74
references.pmid: 20713176
references.citation: Am J Physiol Lung Cell Mol Physiol. 2003 Jun;284(6):L1082-92
references.pmid: 12576296
references.citation: Proc Natl Acad Sci U S A. 2000 May 23;97(11):5895-900
references.pmid: 10823942
references.citation: Invest Ophthalmol Vis Sci. 2001 Jan;42(1):247-54
references.pmid: 11133876
references.citation: Am J Respir Cell Mol Biol. 2001 Dec;25(6):676-84
references.pmid: 11726392
references.citation: J Cell Sci. 1998 Nov;111 ( Pt 21):3209-20
references.pmid: 9763515