title: Localized diacylglycerol-dependent stimulation of Ras and Rap1 during phagocytosis.
abstract: We describe a role for diacylglycerol in the activation of Ras and Rap1 at the phagosomal membrane. During phagocytosis, Ras density was similar on the surface and invaginating areas of the membrane, but activation was detectable only in the latter and in sealed phagosomes. Ras activation was associated with the recruitment of RasGRP3, a diacylglycerol-dependent Ras/Rap1 exchange factor. Recruitment to phagosomes of RasGRP3, which contains a C1 domain, parallels and appears to be due to the formation of diacylglycerol. Accordingly, Ras and Rap1 activation was precluded by antagonists of phospholipase C and of diacylglycerol binding. Ras is dispensable for phagocytosis but controls activation of extracellular signal-regulated kinase, which is partially impeded by diacylglycerol inhibitors. By contrast, cross-activation of complement receptors by stimulation of Fcgamma receptors requires Rap1 and involves diacylglycerol. We suggest a role for diacylglycerol-dependent exchange factors in the activation of Ras and Rap1, which govern distinct processes induced by Fcgamma receptor-mediated phagocytosis to enhance the innate immune response.
authors.affiliation: Department of Chemistry and Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada.
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Botelho
authors.forename: Rene E
authors.initials: RE
authors.lastname: Harrison
authors.forename: James C
authors.initials: JC
authors.lastname: Stone
authors.forename: John F
authors.initials: JF
authors.lastname: Hancock
authors.forename: Mark R
authors.initials: MR
authors.lastname: Philips
authors.forename: Jenny
authors.initials: J
authors.lastname: Jongstra-Bilen
authors.forename: David
authors.initials: D
authors.lastname: Mason
authors.forename: Jonathan
authors.initials: J
authors.lastname: Plumb
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gold
authors.forename: Sergio
authors.initials: S
authors.lastname: Grinstein
mesh_terms: D000818:Animals; D004075:Diglycerides / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D007113:Immunity, Innate; D007074:Immunoglobulin G / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods; D010587:Phagocytosis; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D015398:Signal Transduction; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D004075:Diglycerides; D007074:Immunoglobulin G; D020033:Protein Isoforms; D020827:rap1 GTP-Binding Proteins; D018631:ras Proteins
references.citation: J Biol Chem. 1994 Jul 29;269(30):19553-8
references.pmid: 7518459
references.citation: Blood. 2003 Aug 15;102(4):1414-20
references.pmid: 12730099
references.citation: J Cell Biol. 2000 Dec 25;151(7):1353-68
references.pmid: 11134066
references.citation: J Cell Sci. 2001 May;114(Pt 9):1603-8
references.pmid: 11309191
references.citation: Blood. 2005 May 1;105(9):3648-54
references.pmid: 15657177
references.citation: Science. 1998 May 15;280(5366):1082-6
references.pmid: 9582122
references.citation: J Immunol. 2000 Sep 1;165(5):2809-17
references.pmid: 10946313
references.citation: Nat Cell Biol. 2001 Apr;3(4):368-75
references.pmid: 11283610
references.citation: J Exp Med. 2003 Dec 15;198(12):1841-51
references.pmid: 14676298
references.citation: J Biol Chem. 2003 Feb 14;278(7):4572-81
references.pmid: 12458225
references.citation: J Cell Biol. 1998 Feb 9;140(3):485-98
references.pmid: 9456311
references.citation: J Biol Chem. 2002 Aug 23;277(34):31089-98
references.pmid: 12070163
references.citation: J Biol Chem. 1998 Oct 30;273(44):29218-23
references.pmid: 9786933
references.citation: Mol Pharmacol. 2000 May;57(5):840-6
references.pmid: 10779365
references.citation: J Leukoc Biol. 2002 Oct;72(4):657-67
references.pmid: 12377934
references.citation: Cancer Res. 2001 Feb 1;61(3):943-9
references.pmid: 11221888
references.citation: J Cell Biol. 2000 Mar 20;148(6):1151-8
references.pmid: 10725328
references.citation: Nat Immunol. 2001 Jan;2(1):29-36
references.pmid: 11135575
references.citation: Oncogene. 1997 Feb 6;14(5):623-5
references.pmid: 9053862
references.citation: J Biol Chem. 1999 Jan 15;274(3):1240-7
references.pmid: 9880492
references.citation: Genes Dev. 2000 Jan 1;14(1):11-6
references.pmid: 10640270
references.citation: J Immunol. 1999 Dec 1;163(11):6023-34
references.pmid: 10570290
references.citation: J Leukoc Biol. 2001 Oct;70(4):649-58
references.pmid: 11590203
references.citation: J Immunol. 1999 Sep 15;163(6):3388-95
references.pmid: 10477609
references.citation: J Cell Biol. 1991 May;113(4):757-67
references.pmid: 2026648
references.citation: J Cell Sci. 1994 Jun;107 ( Pt 6):1661-70
references.pmid: 7962206
references.citation: J Cell Biol. 2001 Mar 19;152(6):1135-43
references.pmid: 11257115
references.citation: J Cell Biol. 1988 Mar;106(3):657-66
references.pmid: 3346321
references.citation: EMBO J. 2003 Jul 1;22(13):3326-36
references.pmid: 12839994
references.citation: J Biol Chem. 2003 Nov 14;278(46):45720-9
references.pmid: 12941957
references.citation: J Exp Med. 1996 Sep 1;184(3):1027-35
references.pmid: 9064320
references.citation: Curr Opin Cell Biol. 2003 Apr;15(2):136-42
references.pmid: 12648668
references.citation: J Cell Biol. 2002 Dec 23;159(6):939-44
references.pmid: 12499353
references.citation: J Biol Chem. 2000 Aug 18;275(33):25488-93
references.pmid: 10835426
references.citation: Mol Biol Cell. 1999 Feb;10(2):393-406
references.pmid: 9950684
references.citation: Curr Biol. 2000 Aug 24;10(16):974-8
references.pmid: 10985384
references.citation: EMBO J. 2002 Feb 1;21(3):251-8
references.pmid: 11823418
references.citation: Nat Cell Biol. 2002 May;4(5):343-50
references.pmid: 11988737
references.citation: Science. 2006 Jul 21;313(5785):347-51
references.pmid: 16857939
references.citation: Mol Biol Cell. 2006 Feb;17(2):799-813
references.pmid: 16319178
references.citation: Mol Biol Cell. 2002 Apr;13(4):1215-26
references.pmid: 11950933
references.citation: J Leukoc Biol. 1999 Jun;65(6):854-62
references.pmid: 10380910
references.citation: Blood. 2000 May 15;95(10):3199-203
references.pmid: 10807788
references.citation: J Cell Biol. 2004 Feb 2;164(3):461-70
references.pmid: 14757755
references.citation: EMBO J. 1998 Nov 2;17(21):6219-29
references.pmid: 9799231
references.citation: J Biol Chem. 2002 Jul 12;277(28):25756-74
references.pmid: 11956218
references.citation: Proc Natl Acad Sci U S A. 2004 Nov 23;101(47):16612-7
references.pmid: 15545601
references.citation: Annu Rev Immunol. 1997;15:203-34
references.pmid: 9143687
references.citation: J Leukoc Biol. 1993 Apr;53(4):427-38
references.pmid: 8482923
references.citation: J Immunol. 1997 Apr 1;158(7):3433-8
references.pmid: 9120304
references.citation: Nat Immunol. 2000 Oct;1(4):317-21
references.pmid: 11017103
references.citation: J Immunol. 1990 Feb 15;144(4):1411-7
references.pmid: 2105997
references.citation: Ann Hematol. 1998 Jun;76(6):231-48
references.pmid: 9692811
references.citation: J Cell Biol. 2001 Jun 25;153(7):1369-80
references.pmid: 11425868
references.citation: Inflammation. 1998 Feb;22(1):67-82
references.pmid: 9484651
references.citation: J Biol Chem. 1995 May 5;270(18):10777-83
references.pmid: 7537738
references.citation: Semin Immunol. 2001 Dec;13(6):347-55
references.pmid: 11708890
references.citation: Cell. 1999 Jul 9;98(1):69-80
references.pmid: 10412982
references.citation: Curr Opin Immunol. 2002 Feb;14(1):136-45
references.pmid: 11790544
references.citation: Curr Opin Immunol. 1996 Feb;8(1):36-40
references.pmid: 8729444
references.citation: Nature. 2003 Aug 7;424(6949):694-8
references.pmid: 12845332