title: Arabidopsis VILLIN5, an actin filament bundling and severing protein, is necessary for normal pollen tube growth.
abstract: A dynamic actin cytoskeleton is essential for pollen germination and tube growth. However, the molecular mechanisms underlying the organization and turnover of the actin cytoskeleton in pollen remain poorly understood. Villin plays a key role in the formation of higher-order structures from actin filaments and in the regulation of actin dynamics in eukaryotic cells. It belongs to the villin/gelsolin/fragmin superfamily of actin binding proteins and is composed of six gelsolin-homology domains at its core and a villin headpiece domain at its C terminus. Recently, several villin family members from plants have been shown to sever, cap, and bundle actin filaments in vitro. Here, we characterized a villin isovariant, Arabidopsis thaliana VILLIN5 (VLN5), that is highly and preferentially expressed in pollen. VLN5 loss-of-function retarded pollen tube growth and sensitized actin filaments in pollen grains and tubes to latrunculin B. In vitro biochemical analyses revealed that VLN5 is a typical member of the villin family and retains a full suite of activities, including barbed-end capping, filament bundling, and calcium-dependent severing. The severing activity was confirmed with time-lapse evanescent wave microscopy of individual actin filaments in vitro. We propose that VLN5 is a major regulator of actin filament stability and turnover that functions in concert with oscillatory calcium gradients in pollen and therefore plays an integral role in pollen germination and tube growth.
authors.affiliation: Center for Signal Transduction and Metabolomics, Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Qu
authors.forename: Chanchan
authors.initials: C
authors.lastname: Bao
authors.forename: Parul
authors.initials: P
authors.lastname: Khurana
authors.forename: Qiannan
authors.initials: Q
authors.lastname: Wang
authors.forename: Yurong
authors.initials: Y
authors.lastname: Xie
authors.forename: Yiyan
authors.initials: Y
authors.lastname: Zheng
authors.forename: Naizhi
authors.initials: N
authors.lastname: Chen
authors.forename: Laurent
authors.initials: L
authors.lastname: Blanchoin
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Staiger
authors.forename: Shanjin
authors.initials: S
authors.lastname: Huang
mesh_terms: D000199:Actins / Q000378:metabolism*; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D053205:Pollen Tube / Q000254:growth & development*; D018749:RNA, Plant / Q000235:genetics; D053778:Thiazolidines / Q000494:pharmacology
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D008840:Microfilament Proteins; D018749:RNA, Plant; D053778:Thiazolidines; C026615:villin; D015638:Cytochalasin D; C037068:latrunculin B; D002118:Calcium
references.citation: Plant Cell. 1997 Aug;9(8):1445-1457
references.pmid: 12237391
references.citation: J Mol Biol. 1994 Aug 19;241(3):480-2
references.pmid: 8064860
references.citation: Plant Cell Physiol. 2003 Oct;44(10):1088-99
references.pmid: 14581634
references.citation: Plant Cell. 2005 Feb;17(2):486-501
references.pmid: 15659626
references.citation: Proc Natl Acad Sci U S A. 2001 Dec 18;98(26):15009-13
references.pmid: 11742068
references.citation: J Biol Chem. 2003 Nov 7;278(45):44832-42
references.pmid: 12947123
references.citation: J Biol Chem. 2000 Nov 10;275(45):35457-70
references.pmid: 10956642
references.citation: Plant J. 2000 Dec;24(5):625-36
references.pmid: 11123801
references.citation: Plant Cell. 2005 Aug;17(8):2296-313
references.pmid: 15994911
references.citation: Curr Opin Plant Biol. 2008 Dec;11(6):662-71
references.pmid: 18977167
references.citation: J Biol Chem. 1971 Aug 10;246(15):4866-71
references.pmid: 4254541
references.citation: Plant Physiol. 2008 Apr;146(4):1611-21
references.pmid: 18263780
references.citation: Plant Physiol. 2003 Jun;132(2):640-52
references.pmid: 12805594
references.citation: Nature. 2000 Apr 27;404(6781):1007-11
references.pmid: 10801131
references.citation: Plant Cell. 2006 Sep;18(9):2194-206
references.pmid: 16905656
references.citation: Mol Biol Cell. 2006 Apr;17(4):1946-58
references.pmid: 16436516
references.citation: Annu Rev Plant Biol. 2008;59:547-72
references.pmid: 18444907
references.citation: Curr Biol. 2006 Oct 10;16(19):1924-30
references.pmid: 17027489
references.citation: Plant Physiol. 2008 Aug;147(4):1619-36
references.pmid: 18480376
references.citation: Curr Opin Plant Biol. 2006 Dec;9(6):579-88
references.pmid: 17010659
references.citation: Plant Cell. 2009 Dec;21(12):3868-84
references.pmid: 20023198
references.citation: FEBS Lett. 2008 Jun 18;582(14):2128-39
references.pmid: 18307996
references.citation: Plant Cell. 2002 Sep;14(9):2175-90
references.pmid: 12215514
references.citation: Dev Biol. 2000 Jun 1;222(1):84-98
references.pmid: 10885748
references.citation: Plant Physiol. 2005 Jun;138(2):744-56
references.pmid: 15908605
references.citation: J Biol Chem. 2004 May 28;279(22):23364-75
references.pmid: 15039433
references.citation: Mol Biol Cell. 2001 Aug;12(8):2534-45
references.pmid: 11514633
references.citation: Plant J. 1997 Oct;12(4):957-63
references.pmid: 9375406
references.citation: Plant Cell. 2007 Jun;19(6):1930-46
references.pmid: 17586658
references.citation: Cell Motil Cytoskeleton. 1997;36(4):323-38
references.pmid: 9096955
references.citation: J Cell Biol. 2009 Jan 26;184(2):269-80
references.pmid: 19171759
references.citation: Biochemistry. 1984 Dec 4;23(25):6099-102
references.pmid: 6525347
references.citation: Plant Cell Physiol. 2005 Oct;46(10):1690-703
references.pmid: 16100394
references.citation: J Cell Biol. 1999 Aug 23;146(4):819-30
references.pmid: 10459016
references.citation: J Cell Biol. 1984 Sep;99(3):769-77
references.pmid: 6540783
references.citation: Cell. 1981 May;24(2):471-80
references.pmid: 6894565
references.citation: Cell. 1989 Nov 3;59(3):461-75
references.pmid: 2680107
references.citation: Bioessays. 1990 Sep;12(9):403-8
references.pmid: 2256904
references.citation: Development. 1999 Dec;126(24):5645-57
references.pmid: 10572041
references.citation: Plant Physiol. 2000 Jun;123(2):645-54
references.pmid: 10859194
references.citation: J Integr Plant Biol. 2009 Aug;51(8):740-50
references.pmid: 19686371
references.citation: Annu Rev Cell Dev Biol. 2001;17:159-87
references.pmid: 11687487
references.citation: PLoS One. 2009 May 29;4(5):e5744
references.pmid: 19478943
references.citation: Cell Mol Life Sci. 2004 Oct;61(19-20):2614-23
references.pmid: 15526166
references.citation: Plant Physiol. 2004 Dec;136(4):3968-78
references.pmid: 15557099
references.citation: Plant Cell. 2002 Oct;14(10):2613-26
references.pmid: 12368508
references.citation: Mol Biol Cell. 2007 Mar;18(3):827-38
references.pmid: 17182858
references.citation: Methods Enzymol. 2006;406:215-34
references.pmid: 16472660
references.citation: Planta. 2005 Apr;221(1):95-104
references.pmid: 15747143
references.citation: J Biol Chem. 2007 Sep 7;282(36):26528-41
references.pmid: 17606613
references.citation: Plant Physiol. 2000 Jan;122(1):35-48
references.pmid: 10631247
references.citation: Cell Motil Cytoskeleton. 1992;23(2):133-44
references.pmid: 1333365
references.citation: Plant Physiol. 1998 Apr;116(4):1421-9
references.pmid: 9536060
references.citation: J Cell Biol. 1987 Oct;105(4):1473-8
references.pmid: 3312229
references.citation: FEBS Lett. 2003 Sep 25;552(2-3):75-81
references.pmid: 14527663
references.citation: Science. 2009 Nov 27;326(5957):1208-12
references.pmid: 19965462
references.citation: Plant Cell. 1999 Dec;11(12):2349-63
references.pmid: 10590163
references.citation: J Exp Bot. 2010 Apr;61(7):1969-86
references.pmid: 20159884
references.citation: Biochemistry. 1984 Jun 5;23(12):2613-21
references.pmid: 6432033
references.citation: EMBO J. 1987 Dec 20;6(13):3901-7
references.pmid: 3327686
references.citation: Plant Cell. 1997 Nov;9(11):1999-2010
references.pmid: 12237353
references.citation: Mol Cell. 2006 Oct 6;24(1):13-23
references.pmid: 17018289
references.citation: J Biol Chem. 2001 Sep 28;276(39):36163-7
references.pmid: 11500485
references.citation: Cell Motil Cytoskeleton. 2009 Nov;66(11):940-57
references.pmid: 19504571
references.citation: Plant Cell. 2010 Aug;22(8):2727-48
references.pmid: 20807878
references.citation: J Biol Chem. 2007 Nov 16;282(46):33599-33608
references.pmid: 17827159
references.citation: Planta. 2000 Apr;210(5):836-43
references.pmid: 10805457
references.citation: Curr Opin Plant Biol. 2007 Dec;10(6):549-56
references.pmid: 17936064
references.citation: Curr Opin Plant Biol. 2006 Dec;9(6):554-62
references.pmid: 17011229
references.citation: J Cell Biol. 1979 Dec;83(3):667-73
references.pmid: 574874
references.citation: Biochem Biophys Res Commun. 1998 Aug 10;249(1):61-5
references.pmid: 9705832
references.citation: Proc Natl Acad Sci U S A. 1979 May;76(5):2321-5
references.pmid: 287075
references.citation: Cell. 1994 Jul 29;78(2):291-301
references.pmid: 8044841