title: FRIGIDA and related proteins have a conserved central domain and family specific N- and C- terminal regions that are functionally important.
abstract: Arabidopsis accessions are either winter-annuals, which require cold winter temperatures for spring flowering, or rapid-cycling summer annuals. Typically, winter annual accessions have functional FRIGIDA (FRI) and FRIGIDA-LIKE 1 (FRL1) proteins that promote high expression of FLOWERING LOCUS C (FLC), which prevents flowering until after winter. In contrast, many rapid-cycling accessions have low FLC levels because FRI is inactive. Using biochemical, functional and bioinformatic approaches, we show that FRI and FRL1 contain a stable, central domain that is conserved across the FRI superfamily. This core domain is monomeric in solution and primarily alpha-helical. We analysed the ability of several FRI deletion constructs to function in Arabidopsis plants. Our findings suggest that the C-terminus, which is predicted to be disordered, is required for FRI to promote FLC expression and may mediate protein:protein interactions. The contribution of the FRI N-terminus appears to be limited, as constructs missing these residues retained significant activity when expressed at high levels. The important N- and C-terminal regions differ between members of the FRI superfamily and sequence analysis identified five FRI families with distinct expression patterns in Arabidopsis, suggesting the families have separate biological roles.
authors.affiliation: Biochemistry Department, University of Otago, Dunedin 9054, New Zealand.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Risk
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Laurie
authors.forename: Richard C
authors.initials: RC
authors.lastname: Macknight
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Day
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D002942:Circular Dichroism; D017124:Conserved Sequence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D030821:Plants, Genetically Modified; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D012995:Solubility; D013329:Structure-Activity Relationship; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; C414613:FRI protein, Arabidopsis; C518088:FRL1 protein, Arabidopsis
references.citation: Plant Cell. 1999 May;11(5):949-56
references.pmid: 10330478
references.citation: Science. 2000 Oct 13;290(5490):344-7
references.pmid: 11030654
references.citation: Proc Natl Acad Sci U S A. 1997 Oct 28;94(22):11893-8
references.pmid: 9342333
references.citation: Genes Dev. 1996 Jul 1;10(13):1683-98
references.pmid: 8682298
references.citation: Anal Biochem. 1990 Nov 15;191(1):110-8
references.pmid: 2077933
references.citation: Proc Natl Acad Sci U S A. 2003 Oct 28;100(22):13099-104
references.pmid: 14557548
references.citation: Annu Rev Cell Dev Biol. 2009;25:277-99
references.pmid: 19575660
references.citation: J Cell Biol. 1992 Sep;118(6):1287-95
references.pmid: 1522107
references.citation: Plant J. 2009 Mar;57(5):918-31
references.pmid: 19121105
references.citation: Mol Cell Biol. 1996 Jun;16(6):2579-84
references.pmid: 8649365
references.citation: Plant Cell. 1999 Mar;11(3):445-58
references.pmid: 10072403
references.citation: Nature. 2009 Dec 10;462(7274):799-802
references.pmid: 20010688
references.citation: Development. 2005 Dec;132(24):5471-8
references.pmid: 16291783
references.citation: Proc Natl Acad Sci U S A. 2004 Mar 2;101(9):3281-5
references.pmid: 14973192
references.citation: Plant Cell. 2006 Nov;18(11):2985-98
references.pmid: 17138694
references.citation: Nat Rev Mol Cell Biol. 2005 Mar;6(3):197-208
references.pmid: 15738986
references.citation: Trends Plant Sci. 2007 Aug;12(8):352-7
references.pmid: 17629542
references.citation: Protein Sci. 1995 Jun;4(6):1088-99
references.pmid: 7549873
references.citation: Biochemistry. 1981 Jan 6;20(1):33-7
references.pmid: 7470476
references.citation: Dev Cell. 2008 Jun;14(6):854-66
references.pmid: 18486559
references.citation: Nucleic Acids Res. 2009 Jan;37(Database issue):D205-10
references.pmid: 18984618
references.citation: PLoS Genet. 2008 Aug 22;4(8):e1000077
references.pmid: 18725930
references.citation: Development. 2006 Dec;133(23):4699-707
references.pmid: 17079264
references.citation: Plant Mol Biol. 2000 Apr;42(6):819-32
references.pmid: 10890530
references.citation: Plant J. 2009 Aug;59(3):488-98
references.pmid: 19368695
references.citation: Proc Natl Acad Sci U S A. 2008 Nov 4;105(44):16831-6
references.pmid: 18854416
references.citation: Proc Natl Acad Sci U S A. 2003 May 13;100(10):6263-8
references.pmid: 12730378
references.citation: Cell. 1990 Oct 5;63(1):109-18
references.pmid: 2208274
references.citation: Proc Natl Acad Sci U S A. 2008 Jun 24;105(25):8795-800
references.pmid: 18550839
references.citation: Bioessays. 2004 Apr;26(4):363-73
references.pmid: 15057934
references.citation: Plant Physiol. 2003 Jun;132(2):1107-14
references.pmid: 12805638
references.citation: Genetics. 2005 Jul;170(3):1197-207
references.pmid: 15911588
references.citation: Nat Methods. 2008 Feb;5(2):135-46
references.pmid: 18235434
references.citation: Nature. 1977 Mar 17;266(5599):235-9
references.pmid: 557727
references.citation: Genes Dev. 2004 Nov 15;18(22):2774-84
references.pmid: 15520273
references.citation: Mol Cell Biol. 2008 Feb;28(4):1348-60
references.pmid: 18070919
references.citation: Plant Physiol. 2006 Dec;142(4):1728-38
references.pmid: 17056759
references.citation: Plant J. 2005 Jul;43(1):153-63
references.pmid: 15960624
references.citation: Plant Cell. 2009 Oct;21(10):3257-69
references.pmid: 19855050
references.citation: Plant Cell Physiol. 2008 Nov;49(11):1634-44
references.pmid: 18829588
references.citation: Proc Natl Acad Sci U S A. 2003 Aug 19;100(17):10102-7
references.pmid: 12904584
references.citation: Nucleic Acids Res. 2010 Jan;38(1):265-78
references.pmid: 19864257
references.citation: Cell. 2006 May 19;125(4):655-64
references.pmid: 16713560
references.citation: Plant Cell. 2009 Jun;21(6):1733-46
references.pmid: 19567704
references.citation: Plant J. 2009 Sep;59(5):814-25
references.pmid: 19453442
references.citation: Plant Physiol. 2005 Apr;137(4):1420-34
references.pmid: 15778459
references.citation: Curr Opin Plant Biol. 2009 Feb;12(1):75-80
references.pmid: 18938104
references.citation: Plant Cell. 2008 Mar;20(3):580-8
references.pmid: 18375656
references.citation: Plant Physiol. 2005 Jun;138(2):1163-73
references.pmid: 15908596
references.citation: Nucleic Acids Res. 2004 Jul 1;32(Web Server issue):W668-73
references.pmid: 15215473
references.citation: Biochemistry. 2005 Feb 15;44(6):1989-2000
references.pmid: 15697224
references.citation: Cell Death Differ. 2007 Jan;14(1):128-36
references.pmid: 16645638
references.citation: Plant Physiol. 2009 Jul;150(3):1611-8
references.pmid: 19429606