title: A novel ROP/RAC GTPase effector integrates plant cell form and pattern formation.
abstract: ROPs/RACs are the only known signaling Ras superfamily small GTPases in plants. As such they have been suggested to function as central regulators of diverse signaling cascades. The ROP/RAC signaling networks are largely unknown, however, because only few of their effector proteins have been identified. In a paper that was published in the June 5, 2007 issue of Current Biology we described the identification of a novel ROP/RAC effector designated ICR1 (Interactor of Constitutive active ROPs 1). We demonstrated that ICR1 functions as a scaffold that interacts with diverse but specific group of proteins including SEC3 subunit of the exocyst vesicle tethering complex. ICR1-SEC3 complexes can interact with ROPs in vivo and are thereby recruited to the plasma membrane. ICR1 knockdown or silencing leads to cell deformation and loss of the root stem cells population, and ectopic expression of ICR1 phenocopies activated ROPs/RACs. ICR1 presents a new paradigm in ROP/RAC signaling and integrates mechanisms regulating cell form and pattern formation at the whole plant level.
authors.affiliation: Department of Plant Sciences; Tel Aviv University; Tel Aviv, Israel.
authors.forename: Daria
authors.initials: D
authors.lastname: Bloch
authors.forename: Ora
authors.initials: O
authors.lastname: Hazak
authors.forename: Meirav
authors.initials: M
authors.lastname: Lavy
authors.forename: Shaul
authors.initials: S
authors.lastname: Yalovsky
references.citation: Mol Cell Biol. 2007 Mar;27(6):2144-54
references.pmid: 17242203
references.citation: Plant Physiol. 2005 Aug;138(4):2005-18
references.pmid: 16040664
references.citation: EMBO J. 2001 Jun 1;20(11):2779-88
references.pmid: 11387211
references.citation: Science. 2006 Dec 1;314(5804):1458-61
references.pmid: 17095657
references.citation: Plant Cell. 2002 Apr;14(4):777-94
references.pmid: 11971134
references.citation: Trends Plant Sci. 2006 Feb;11(2):57-9
references.pmid: 16406756
references.citation: Cell Biol Int. 2003;27(3):199-201
references.pmid: 12681307
references.citation: Mol Biol Cell. 2005 Apr;16(4):1913-27
references.pmid: 15703216
references.citation: Mol Biol Cell. 2003 Dec;14(12):4770-82
references.pmid: 12960429
references.citation: Plant Cell. 2002 Apr;14(4):763-76
references.pmid: 11971133
references.citation: Plant J. 2005 May;42(4):492-503
references.pmid: 15860008
references.citation: Plant J. 2006 Jun;46(6):1018-31
references.pmid: 16805734
references.citation: J Biol Chem. 2004 Feb 20;279(8):7098-104
references.pmid: 14660612
references.citation: Cell. 2005 Mar 11;120(5):687-700
references.pmid: 15766531
references.citation: Trends Cell Biol. 2002 Jun;12(6):247-9
references.pmid: 12074877
references.citation: Plant Cell. 2006 Nov;18(11):3033-46
references.pmid: 17098809
references.citation: Cell. 2003 Nov 26;115(5):591-602
references.pmid: 14651850
references.citation: Curr Biol. 2007 Jun 5;17(11):947-52
references.pmid: 17493810
references.citation: Plant Physiol. 2003 Dec;133(4):1791-808
references.pmid: 14605221
references.citation: Bioessays. 2007 Apr;29(4):356-70
references.pmid: 17373658
references.citation: EMBO J. 1996 Dec 2;15(23):6483-94
references.pmid: 8978675
references.citation: Nat Cell Biol. 2001 Apr;3(4):353-60
references.pmid: 11283608
references.citation: Development. 2001 Oct;128(20):4057-67
references.pmid: 11641228
references.citation: Genetics. 2000 Dec;156(4):1959-71
references.pmid: 11102387
references.citation: J Cell Biol. 2005 Apr 11;169(1):127-38
references.pmid: 15824136
references.citation: J Cell Biol. 2001 Mar 5;152(5):1019-32
references.pmid: 11238457
references.citation: Curr Biol. 2006 Nov 7;16(21):2143-9
references.pmid: 17084699
references.citation: Cell. 2004 Oct 1;119(1):109-20
references.pmid: 15454085
references.citation: Plant Cell. 1999 Sep;11(9):1731-42
references.pmid: 10488239
references.citation: FEBS Lett. 2007 May 22;581(11):2098-104
references.pmid: 17382322
references.citation: Plant Physiol. 2003 Jul;132(3):1623-30
references.pmid: 12857841
references.citation: Plant Cell. 1996 Feb;8(2):293-303
references.pmid: 12239385
references.citation: Traffic. 2004 Apr;5(4):255-64
references.pmid: 15030567