title: Sprouty2 association with B-Raf is regulated by phosphorylation and kinase conformation.
abstract: Sprouty2 is a feedback regulator that controls the Ras/Raf/MEK/extracellular signal-regulated kinase mitogen-activated protein kinase (MAPK) pathway at multiple levels, one way being through direct interaction with Raf kinases. Consistent with a role as a tumor suppressor, Sprouty2 expression is often down-regulated in human cancers. However, Sprouty2 is up-regulated in some cancers, suggesting the existence of posttranscriptional mechanisms that permit evasion of Sprouty2-mediated antitumorigenic properties. We report that MAPK activation induces Sprouty2 phosphorylation on six serine residues, which reduced Sprouty2 association with wild-type B-Raf. Mutation of these six serines to nonphosphorylatable alanines increased the ability of Sprouty2 to inhibit growth factor-induced MAPK activation. Oncogenic B-Raf mutants such as B-Raf V600E did not associate with Sprouty2, but this resistance to Sprouty2 binding was not due to phosphorylation. Instead, the active kinase conformation induced by oncogenic mutation prevents Sprouty2 binding. These results reveal a dual mechanism that affects the Sprouty2/B-Raf interaction: Sprouty phosphorylation and B-Raf conformation.
authors.affiliation: The Beatson Institute for Cancer Research, Glasgow, United Kingdom.
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Brady
authors.forename: Mathew L
authors.initials: ML
authors.lastname: Coleman
authors.forename: June
authors.initials: J
authors.lastname: Munro
authors.forename: Stephan M
authors.initials: SM
authors.lastname: Feller
authors.forename: Nicolas A
authors.initials: NA
authors.lastname: Morrice
authors.forename: Michael F
authors.initials: MF
authors.lastname: Olson
mesh_terms: D000818:Animals; D001665:Binding Sites; D004789:Enzyme Activation; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D008565:Membrane Proteins; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D009369:Neoplasms / Q000201:enzymology* / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D048493:Proto-Oncogene Proteins B-raf / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C485561:SPRY2 protein, human; D048493:Proto-Oncogene Proteins B-raf
references.citation: Biophys J. 2004 Nov;87(5):L01-2
references.pmid: 15454405
references.citation: Development. 1999 Sep;126(18):4139-47
references.pmid: 10457022
references.citation: Mech Dev. 1999 Mar;81(1-2):213-6
references.pmid: 10330503
references.citation: Cancer Lett. 2006 Oct 28;242(2):141-50
references.pmid: 16469433
references.citation: Mol Cell Biol. 2006 Mar;26(5):1898-907
references.pmid: 16479008
references.citation: Lancet. 2002 Apr 13;359(9314):1301-7
references.pmid: 11965276
references.citation: Cell. 1998 Jan 23;92(2):253-63
references.pmid: 9458049
references.citation: Nat Rev Mol Cell Biol. 2004 Jun;5(6):441-50
references.pmid: 15173823
references.citation: Oncogene. 2008 Dec 4;27(57):7150-61
references.pmid: 18806830
references.citation: Cancer Sci. 2007 Jun;98(6):815-21
references.pmid: 17388787
references.citation: Mol Cancer Res. 2007 May;5(5):509-20
references.pmid: 17510316
references.citation: Cancer Res. 2004 Aug 15;64(16):5556-9
references.pmid: 15313890
references.citation: Cancer Res. 2006 Feb 15;66(4):2048-58
references.pmid: 16489004
references.citation: Mol Cancer Ther. 2003 Aug;2(8):699-709
references.pmid: 12939459
references.citation: J Biol Chem. 2006 Feb 24;281(8):4816-22
references.pmid: 16371366
references.citation: Am J Respir Cell Mol Biol. 2009 Jan;40(1):31-7
references.pmid: 18635814
references.citation: Oncogene. 2004 Jul 1;23(30):5193-202
references.pmid: 15122328
references.citation: Trends Cell Biol. 2006 Jan;16(1):45-54
references.pmid: 16337795
references.citation: Mol Cell Biol. 2008 Oct;28(19):5899-911
references.pmid: 18678649
references.citation: Genes Dev. 2007 Mar 15;21(6):694-707
references.pmid: 17369402
references.citation: Biochem Biophys Res Commun. 2001 Aug 3;285(5):1084-8
references.pmid: 11478764
references.citation: Methods Enzymol. 2006;406:128-40
references.pmid: 16472655
references.citation: Curr Biol. 1999 Feb 25;9(4):219-22
references.pmid: 10074434
references.citation: Mol Cell Proteomics. 2006 Feb;5(2):337-46
references.pmid: 16260767
references.citation: Development. 1999 Oct;126(20):4465-75
references.pmid: 10498682
references.citation: Endocr Relat Cancer. 2006 Sep;13(3):839-49
references.pmid: 16954433
references.citation: Prostate. 2006 May 1;66(6):613-24
references.pmid: 16388505
references.citation: Hepatology. 2008 Apr;47(4):1200-10
references.pmid: 18214995
references.citation: J Biol Chem. 2002 Feb 1;277(5):3195-201
references.pmid: 11698404
references.citation: Nat Cell Biol. 2003 May;5(5):427-32
references.pmid: 12717443
references.citation: EMBO J. 1994 Apr 1;13(7):1610-9
references.pmid: 8157000
references.citation: Cell. 2004 Mar 19;116(6):855-67
references.pmid: 15035987
references.citation: Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4519-24
references.pmid: 19251651
references.citation: J Biol Chem. 2001 Sep 28;276(39):36804-8
references.pmid: 11495895
references.citation: Cancer Res. 2005 Dec 15;65(24):11493-500
references.pmid: 16357158
references.citation: Nat Cell Biol. 2009 Jan;11(1):106-9
references.pmid: 19122596
references.citation: Nat Cell Biol. 2002 Nov;4(11):850-8
references.pmid: 12402043
references.citation: Carcinogenesis. 2005 Jul;26(7):1224-32
references.pmid: 15760917
references.citation: Angiogenesis. 2008;11(1):53-62
references.pmid: 18219583
references.citation: Oncogene. 2005 Mar 24;24(13):2166-74
references.pmid: 15735753
references.citation: J Cell Biol. 2001 Mar 5;152(5):1087-98
references.pmid: 11238463
references.citation: J Biomol Tech. 2002 Sep;13(3):119-30
references.pmid: 19498976