title: Loss of all three calreticulins, CRT1, CRT2 and CRT3, causes  enhanced sensitivity to water stress in Arabidopsis.
abstract: The calreticulin triple knockout mutant shows growth defects in response to abiotic stress. The endoplasmic reticulum (ER) is an essential organelle that is responsible for the folding and maturation of proteins. During ER stress, unfolded protein aggregates accumulate in the cell, leading to the unfolded protein response (UPR). The UPR up-regulates the expression of ER-stress-responsive genes encoding calreticulin (CRT), an ER-localized Ca2+-binding protein. To understand the function of plant CRTs, we generated a triple knockout mutant, t123, which lacks CRT1, CRT2 and CRT3 and examined the roles of calreticulins in abiotic stress tolerance. A triple knockout mutant increased sensitivity to water stress which implies that calreticulins are involved in the Arabidopsis response to water stress. We identified that the cyclophilin AtCYP21-2, which is located in the ER, was specifically enhanced in the t123 mutants. Seed germination of the atcyp21-1 mutant was retarded by water stress. Taken together, these results suggest that regulatory proteins that serve to protect plants from water stress are folded properly in part with the help of calreticulins. The AtCYP21-2 may also participate in this protein-folding process in association with calreticulins.
authors.forename: Jun Hyeok
authors.initials: JH
authors.lastname: Kim
authors.forename: Nguyen Hoai
authors.initials: NH
authors.lastname: Nguyen
authors.forename: Ngoc Trinh
authors.initials: NT
authors.lastname: Nguyen
authors.forename: Suk-Whan
authors.initials: SW
authors.lastname: Hong
authors.forename: Hojoung
authors.initials: H
authors.lastname: Lee
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D037282:Calreticulin / Q000235:genetics / Q000378:metabolism*; D003681:Dehydration; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D018525:Germination / Q000187:drug effects / Q000235:genetics; D008353:Mannitol / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development
chemical_list: D029681:Arabidopsis Proteins; D037282:Calreticulin; D020033:Protein Isoforms; D012333:RNA, Messenger; C584706:calreticulin 3, Arabidopsis; D008353:Mannitol; D000040:Abscisic Acid
references.citation: Cell. 2000 Apr 28;101(3):249-58
references.pmid: 10847680
references.citation: Plant Cell. 2003 Feb;15(2):561-76
references.pmid: 12566592
references.citation: J Exp Bot. 2008;59(4):739-51
references.pmid: 18349049
references.citation: Curr Opin Biotechnol. 1998 Apr 1;9(2):214-9
references.pmid: 9664051
references.citation: Transgenic Res. 2002 Feb;11(1):1-10
references.pmid: 11874098
references.citation: Curr Opin Struct Biol. 2002 Oct;12(5):569-77
references.pmid: 12464307
references.citation: Plant Physiol. 2005 Aug;138(4):1866-76
references.pmid: 16006596
references.citation: Plant Cell. 2008 Dec;20(12):3418-29
references.pmid: 19060110
references.citation: EMBO J. 2009 Nov 4;28(21):3439-49
references.pmid: 19763087
references.citation: Mol Cell. 1998 Jan;1(2):203-11
references.pmid: 9659917
references.citation: Plant Cell Physiol. 2008 Jun;49(6):912-24
references.pmid: 18436549
references.citation: Biochemistry. 1975 Nov 4;14(22):4953-63
references.pmid: 241393
references.citation: DNA Seq. 1992;3(4):247-50
references.pmid: 1296819
references.citation: Plant Physiol. 2001 Nov;127(3):1193-203
references.pmid: 11706198
references.citation: Plant Physiol. 1997 May;114(1):29-37
references.pmid: 9159940
references.citation: J Cell Sci. 2006 Feb 15;119(Pt 4):615-23
references.pmid: 16467570
references.citation: EMBO J. 2002 Jun 3;21(11):2692-702
references.pmid: 12032082
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 11;106(32):13612-7
references.pmid: 19597144
references.citation: Plant Physiol. 2001 Jul;126(3):1092-104
references.pmid: 11457960
references.citation: Proc Natl Acad Sci U S A. 2009 Sep 15;106(37):15973-8
references.pmid: 19717464
references.citation: Nature. 1996 Oct 17;383(6601):637-40
references.pmid: 8857542
references.citation: J Clin Invest. 1990 May;85(5):1379-91
references.pmid: 2332496
references.citation: Plant Physiol. 2004 Apr;134(4):1268-82
references.pmid: 15051864
references.citation: DNA Seq. 1992;2(4):235-40
references.pmid: 1627827
references.citation: Gene. 1995 Nov 20;165(2):219-22
references.pmid: 8522179
references.citation: Plant J. 2012 Feb;69(3):489-500
references.pmid: 21974727
references.citation: Mol Genet Genomics. 2010 Mar;283(3):273-87
references.pmid: 20131066
references.citation: Plant Signal Behav. 2011 Jun;6(6):905-10
references.pmid: 21586899
references.citation: Int J Biochem Cell Biol. 2005 Feb;37(2):260-6
references.pmid: 15474971
references.citation: Curr Biol. 1993 Dec 1;3(12):884-6
references.pmid: 15335825
references.citation: Nature. 1989 Mar 2;338(6210):67-70
references.pmid: 2493138
references.citation: Arch Biochem Biophys. 1999 Nov 15;371(2):149-62
references.pmid: 10545201
references.citation: Apoptosis. 2007 Apr;12(4):631-4
references.pmid: 17278002
references.citation: Plant Cell. 1995 Apr;7(4):391-406
references.pmid: 7773014
references.citation: Plant Mol Biol. 1997 Aug;34(6):897-911
references.pmid: 9290642
references.citation: Biochem J. 1999 Dec 1;344 Pt 2:281-92
references.pmid: 10567207
references.citation: Mol Genet Genomics. 2007 Jun;277(6):713-23
references.pmid: 17318583
references.citation: Trends Biochem Sci. 1994 Mar;19(3):124-8
references.pmid: 8203019
references.citation: Plant Cell. 1994 Jun;6(6):835-43
references.pmid: 7914763
references.citation: J Biol Chem. 2002 Aug 23;277(34):31134-41
references.pmid: 12077116
references.citation: FEBS J. 2005 Jul;272(13):3461-76
references.pmid: 15978049
references.citation: Physiol Plant. 2009 Jun;136(2):127-38
references.pmid: 19453510
references.citation: PLoS One. 2010 Jun 28;5(6):e11342
references.pmid: 20596537