Tobacco GTBP1, a homolog of human heterogeneous nuclear ribonucleoprotein, protects telomeres from aberrant homologous recombination.
Telomeres are nucleoprotein complexes essential for the integrity of eukaryotic chromosomes. Cellular roles of single-stranded telomeric DNA binding proteins have been extensively described in yeast and animals, but our knowledge about plant single-strand telomeric factors is rudimentary. Here, we investigated Nicotiana tabacum G-strand-specific single-stranded telomere binding proteins (GTBPs), homologs of a human heterogeneous nuclear ribonucleoprotein. GTBPs bound specifically to the plant single-stranded (TTTAGGG)(4) telomeric repeat element in vitro and were associated with telomeric sequences in tobacco BY-2 suspension cells. Transgenic plants (35S:RNAi-GTBP1), in which GTBP1 was suppressed, exhibited severe developmental anomalies. In addition, the chromosomes of 35S:RNAi-GTBP1 cells displayed elongated telomeres, frequent formation of extrachromosomal telomeric circles, and numerous abnormal anaphase bridges, indicating that GTBP1 knockdown tobacco plants experienced genome instability. GTBP1 inhibited strand invasion, an initial step in interchromosomal homologous recombination. We propose that GTBP1 plays a critical role in telomere structure and function by preventing aberrant interchromosomal telomeric homologous recombination in tobacco.
Lee
Yong Woo
YW
Department of Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea.
Kim
Woo Taek
WT
D000705:Anaphase; D002478:Cells, Cultured; D018744:DNA, Plant / Q000235:genetics; D055785:Gene Knockdown Techniques; D042822:Genomic Instability; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D016615:Telomere / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism
D018744:DNA, Plant; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D010940:Plant Proteins; D034501:Telomere-Binding Proteins
J Biol Chem. 2003 Jun 13;278(24):21395-407
12646586
Mol Biol Evol. 1987 Jul;4(4):406-25
3447015
Plant Physiol. 2010 Jan;152(1):374-87
19923234
Mol Biol Evol. 2007 Aug;24(8):1596-9
17488738
Cell. 1999 May 14;97(4):503-14
10338214
Plant J. 2009 Jun;58(6):1004-15
19228335
Science. 2001 Mar 2;291(5509):1797-800
11230697
Plant Cell. 2004 Aug;16(8):1959-67
15258263
Cell. 2001 Sep 21;106(6):661-73
11572773
Nat Struct Mol Biol. 2007 Feb;14(2):147-54
17220898
Cell. 2006 Jul 14;126(1):63-77
16839877
Curr Opin Genet Dev. 2001 Apr;11(2):189-98
11250143
Plant Cell. 1998 Oct;10(10):1691-8
9761795
Mol Cell. 2007 Jul 6;27(1):163-9
17612498
Plant Physiol. 2000 Jul;123(3):905-15
10889239
Nature. 1991 Apr 18;350(6319):569-73
1708110
Genes Dev. 2005 Sep 15;19(18):2100-10
16166375
Mol Cell. 2009 Oct 23;36(2):207-18
19854131
Nat Rev Genet. 2005 Aug;6(8):611-22
16136653
Mol Cells. 2009 Jul 31;28(1):57-65
19711043
Proc Natl Acad Sci U S A. 1996 Dec 10;93(25):14422-7
8962067
Nat Rev Genet. 2010 May;11(5):319-30
20351727
Cell. 2004 Oct 29;119(3):355-68
15507207
Science. 2001 May 11;292(5519):1171-5
11349150
Science. 1996 Oct 11;274(5285):249-52
8824190
Nat Struct Mol Biol. 2007 May;14(5):397-405
17417655
Plant J. 2002 Mar;29(5):617-26
11874574
Science. 1995 Dec 8;270(5242):1663-7
7502076
EMBO J. 2006 Oct 4;25(19):4577-85
16990794
Nat Genet. 1997 Oct;17(2):236-9
9326951
PCR Methods Appl. 1994 Aug;4(1):S40-58
9018326
Biochem Biophys Res Commun. 2008 Jul 18;372(1):85-90
18477473
Proc Natl Acad Sci U S A. 2008 Dec 16;105(50):19815-20
19064932
Plant J. 2003 Oct;36(2):271-9
14535890
Plant Physiol Biochem. 2004 Jan;42(1):7-14
15061078
Mol Gen Genet. 1995 Jun 10;247(5):633-8
7603443
Mol Cell Biol. 2005 Jan;25(2):808-18
15632080
Mol Cell Biol. 2005 Sep;25(17):7725-33
16107718
Cell. 2006 Jul 14;126(1):49-62
16839876
Plant J. 2007 Feb;49(3):442-51
17217467
EMBO J. 2007 Aug 8;26(15):3653-61
17627276
Plant Cell. 2004 Dec;16(12):3370-85
15528297
Plant Mol Biol. 2000 Mar;42(4):547-57
10809001
J Biol Chem. 2004 Mar 26;279(13):12812-8
14703514
Mol Cell Biol. 2007 Mar;27(5):1706-15
17189431
Plant Cell. 2009 Feb;21(2):622-41
19234086
Nat Genet. 1998 Jun;19(2):199-202
9620782
Plant Cell. 2007 Jun;19(6):1770-81
17586654
Annu Rev Biochem. 2004;73:177-208
15189140
Curr Opin Cell Biol. 2000 Jun;12(3):378-83
10801465
Mol Cell Biol. 1993 Jul;13(7):4301-10
8321232