title: Exo70 interacts with phospholipids and mediates the targeting of the exocyst to the plasma membrane.
abstract: The exocyst is an octameric protein complex implicated in the tethering of post-Golgi secretory vesicles to the plasma membrane before fusion. The function of individual exocyst components and the mechanism by which this tethering complex is targeted to sites of secretion are not clear. In this study, we report that the exocyst subunit Exo70 functions in concert with Sec3 to anchor the exocyst to the plasma membrane. We found that the C-terminal Domain D of Exo70 directly interacts with phosphatidylinositol 4,5-bisphosphate. In addition, we have identified key residues on Exo70 that are critical for its interaction with phospholipids and the small GTPase Rho3. Further genetic and cell biological analyses suggest that the interaction of Exo70 with phospholipids, but not Rho3, is essential for the membrane association of the exocyst complex. We propose that Exo70 mediates the assembly of the exocyst complex at the plasma membrane, which is a crucial step in the tethering of post-Golgi secretory vesicles for exocytosis.
authors: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6018, USA.
authors: Bing
authors: B
authors: He
authors: Fengong
authors: F
authors: Xi
authors: Xiaoyu
authors: X
authors: Zhang
authors: Jian
authors: J
authors: Zhang
authors: Wei
authors: W
authors: Guo
mesh_terms: D000199:Actins / Q000378:metabolism; D000483:Alleles; D002462:Cell Membrane / Q000378:metabolism*; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D019269:Phosphatidylinositol 4,5-Diphosphate; D010743:Phospholipids / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor); D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D033921:Vesicular Transport Proteins; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000199:Actins; C103132:EXO70 protein, S cerevisiae; D046912:Multiprotein Complexes; D019269:Phosphatidylinositol 4,5-Diphosphate; D010743:Phospholipids; D021122:Protein Subunits; C103130:SEC3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C489795:MSS4 protein, S cerevisiae; C074647:RHO3 protein, S cerevisiae; D020741:rho GTP-Binding Proteins
references: EMBO J. 1998 Sep 15;17(18):5374-87
references: 9736615
references: Proc Natl Acad Sci U S A. 2001 Aug 14;98(17):9648-53
references: 11493706
references: J Mol Biol. 2006 Feb 10;356(1):9-21
references: 16359701
references: J Cell Sci. 2002 Jul 1;115(Pt 13):2627-37
references: 12077354
references: Mol Cell. 2004 Mar 12;13(5):677-88
references: 15023338
references: Cell. 1988 Jun 3;53(5):753-68
references: 3131018
references: Proc Natl Acad Sci U S A. 2006 Feb 28;103(9):3118-23
references: 16492791
references: Nat Struct Mol Biol. 2005 Dec;12(12):1094-100
references: 16249794
references: Mol Biol Cell. 2003 Dec;14(12):4770-82
references: 12960429
references: Mol Biol Cell. 2002 Feb;13(2):542-57
references: 11854411
references: J Cell Biol. 1992 Sep;118(5):1041-56
references: 1512289
references: Mol Biol Cell. 1999 Dec;10(12):4121-33
references: 10588647
references: Nat Cell Biol. 1999 May;1(1):E17-22
references: 10559876
references: Mol Cell Biol. 1999 May;19(5):3580-7
references: 10207081
references: Nat Struct Mol Biol. 2006 Jul;13(7):577-81
references: 16826234
references: J Cell Biol. 1995 Jul;130(2):299-312
references: 7615633
references: J Cell Biol. 2004 Dec 6;167(5):889-901
references: 15583031
references: Mol Biol Cell. 2004 Jan;15(1):24-36
references: 14528018
references: Int Rev Cytol. 2004;233:243-65
references: 15037366
references: J Cell Sci. 2005 May 15;118(Pt 10):2093-104
references: 15890985
references: J Cell Biol. 2007 Mar 12;176(6):771-7
references: 17339375
references: Nature. 2005 Dec 1;438(7068):597-604
references: 16319879
references: EMBO J. 2004 Oct 1;23(19):3747-57
references: 15372071
references: Nat Cell Biol. 2001 Apr;3(4):353-60
references: 11283608
references: Proc Natl Acad Sci U S A. 1995 Nov 7;92(23):10472-6
references: 7479822
references: Trends Cell Biol. 2000 Jun;10(6):251-5
references: 10802541
references: J Biol Chem. 2005 May 27;280(21):20356-64
references: 15788396
references: Methods Enzymol. 1991;194:1-863
references: 2005781
references: J Biol Chem. 1998 Jun 19;273(25):15787-93
references: 9624178
references: Nature. 2006 Oct 12;443(7112):651-7
references: 17035995
references: EMBO J. 2000 Sep 1;19(17):4577-88
references: 10970851
references: J Cell Biol. 2002 Mar 18;156(6):1015-28
references: 11889142
references: Mol Cell. 2005 Jan 21;17(2):181-91
references: 15664188
references: J Cell Biol. 2005 Aug 15;170(4):583-94
references: 16103227
references: Nature. 2005 Dec 1;438(7068):605-11
references: 16319880
references: EMBO J. 1999 Feb 15;18(4):1071-80
references: 10022848
references: Nature. 2003 Apr 10;422(6932):629-33
references: 12687004
references: Cell. 1998 Feb 20;92(4):559-71
references: 9491896
references: Mol Biol Cell. 2005 Mar;16(3):1500-12
references: 15647373
references: J Cell Biol. 2005 Jul 18;170(2):273-83
references: 16027223
references: J Biol Chem. 2001 Dec 14;276(50):46745-50
references: 11595741
references: Annu Rev Biophys Biomol Struct. 2002;31:151-75
references: 11988466
references: Traffic. 2000 Aug;1(8):588-97
references: 11208146
references: J Biol Chem. 1998 Oct 16;273(42):27725-33
references: 9765310