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HP1 Recruitment in the Absence of Argonaute Proteins in


Highly repetitive and transposable element rich regions of the genome must be stabilized by the presence of heterochromatin. A direct role for RNA interference in the establishment of heterochromatin has been demonstrated in fission yeast. In metazoans, which possess multiple RNA–silencing pathways that are both functionally distinct and spatially restricted, whether RNA silencing contributes directly to heterochromatin formation is not clear. Previous studies in Drosophila melanogaster have suggested the involvement of both the AGO2-dependent endogenous small interfering RNA (endo-siRNA) as well as Piwi-interacting RNA (piRNA) silencing pathways. In order to determine if these Argonaute genes are required for heterochromatin formation, we utilized transcriptional reporters and chromatin immunoprecipitation of the critical factor Heterochromatin Protein 1 (HP1) to monitor the heterochromatic state of piRNA clusters, which generate both endo-siRNAs and the bulk of piRNAs. Surprisingly, we find that mutation of AGO2 or piwi increases silencing at piRNA clusters corresponding to an increase of HP1 association. Furthermore, loss of piRNA production from a single piRNA cluster results in genome-wide redistribution of HP1 and reduction of silencing at a distant heterochromatic site, suggesting indirect effects on HP1 recruitment. Taken together, these results indicate that heterochromatin forms independently of endo-siRNA and piRNA pathways.


Vyšlo v časopise: HP1 Recruitment in the Absence of Argonaute Proteins in. PLoS Genet 6(3): e32767. doi:10.1371/journal.pgen.1000880
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1000880

Souhrn

Highly repetitive and transposable element rich regions of the genome must be stabilized by the presence of heterochromatin. A direct role for RNA interference in the establishment of heterochromatin has been demonstrated in fission yeast. In metazoans, which possess multiple RNA–silencing pathways that are both functionally distinct and spatially restricted, whether RNA silencing contributes directly to heterochromatin formation is not clear. Previous studies in Drosophila melanogaster have suggested the involvement of both the AGO2-dependent endogenous small interfering RNA (endo-siRNA) as well as Piwi-interacting RNA (piRNA) silencing pathways. In order to determine if these Argonaute genes are required for heterochromatin formation, we utilized transcriptional reporters and chromatin immunoprecipitation of the critical factor Heterochromatin Protein 1 (HP1) to monitor the heterochromatic state of piRNA clusters, which generate both endo-siRNAs and the bulk of piRNAs. Surprisingly, we find that mutation of AGO2 or piwi increases silencing at piRNA clusters corresponding to an increase of HP1 association. Furthermore, loss of piRNA production from a single piRNA cluster results in genome-wide redistribution of HP1 and reduction of silencing at a distant heterochromatic site, suggesting indirect effects on HP1 recruitment. Taken together, these results indicate that heterochromatin forms independently of endo-siRNA and piRNA pathways.


Zdroje

1. GrewalSI

ElginSC

2007 Transcription and RNA interference in the formation of heterochromatin. Nature 447 399 406

2. MasonJM

FrydrychovaRC

BiessmannH

2008 Drosophila telomeres: an exception providing new insights. Bioessays 30 25 37

3. TschierschB

HofmannA

KraussV

DornR

KorgeG

1994 The protein encoded by the Drosophila position-effect variegation suppressor gene Su(var)3-9 combines domains of antagonistic regulators of homeotic gene complexes. EMBOJ 13 3822 3831

4. EissenbergJC

JamesTC

Foster-HartnettDM

HartnettT

NganV

1990 Mutation in a heterochromatin-specific chromosomal protein is associated with suppression of position-effect variegation in Drosophila melanogaster. Proc Natl Acad SciUSA 87 9923 9927

5. VolpeTA

KidnerC

HallIM

TengG

GrewalSI

2002 Regulation of heterochromatic silencing and histone H3 lysine-9 methylation by RNAi. Science 297 1833 1837

6. VerdelA

JiaS

GerberS

SugiyamaT

GygiS

2004 RNAi-mediated targeting of heterochromatin by the RITS complex. Science 303 672 676

7. NomaK

SugiyamaT

CamH

VerdelA

ZofallM

2004 RITS acts in cis to promote RNA interference-mediated transcriptional and post-transcriptional silencing. Nat Genet 36 1174 1180

8. JiaS

NomaK

GrewalSI

2004 RNAi-independent heterochromatin nucleation by the stress-activated ATF/CREB family proteins. Science 304 1971 1976

9. KanohJ

SadaieM

UranoT

IshikawaF

2005 Telomere binding protein Taz1 establishes Swi6 heterochromatin independently of RNAi at telomeres. Curr Biol 15 1808 1819

10. HutvagnerG

SimardMJ

2008 Argonaute proteins: key players in RNA silencing. Nat Rev Mol Cell Biol 9 22 32

11. Brower-TolandB

FindleySD

JiangL

LiuL

YinH

2007 Drosophila PIWI associates with chromatin and interacts directly with HP1a. Genes Dev 21 2300 2311

12. RehwinkelJ

NatalinP

StarkA

BrenneckeJ

CohenSM

2006 Genome-wide analysis of mRNAs regulated by Drosha and Argonaute proteins in Drosophila melanogaster. Mol Cell Biol 26 2965 2975

13. WilliamsRW

RubinGM

2002 ARGONAUTE1 is required for efficient RNA interference in Drosophila embryos. Proc Natl Acad SciUSA 99 6889 6894

14. WangL

LigoxygakisP

2006 Pathogen recognition and signalling in the Drosophila innate immune response. Immunobiology 211 251 261

15. HammondSM

BoettcherS

CaudyAA

KobayashiR

HannonGJ

2001 Argonaute2, a link between genetic and biochemical analyses of RNAi. Science 293 1146 1150

16. CzechB

MaloneCD

ZhouR

StarkA

SchlingeheydeC

2008 An endogenous small interfering RNA pathway in Drosophila. Nature 453 798 802

17. KawamuraY

SaitoK

KinT

OnoY

AsaiK

2008 Drosophila endogenous small RNAs bind to Argonaute 2 in somatic cells. Nature 453 793 797

18. ChungWJ

OkamuraK

MartinR

LaiEC

2008 Endogenous RNA interference provides a somatic defense against Drosophila transposons. Curr Biol 18 795 802

19. GhildiyalM

SeitzH

HorwichMD

LiC

DuT

2008 Endogenous siRNAs derived from transposons and mRNAs in Drosophila somatic cells. Science 320 1077 1081

20. BrenneckeJ

AravinAA

StarkA

DusM

KellisM

2007 Discrete small RNA-generating loci as master regulators of transposon activity in Drosophila. Cell 128 1089 1103

21. YinH

LinH

2007 An epigenetic activation role of Piwi and a Piwi-associated piRNA in Drosophila melanogaster. Nature 450 304 308

22. SaitoK

NishidaKM

MoriT

KawamuraY

MiyoshiK

2006 Specific association of Piwi with rasiRNAs derived from retrotransposon and heterochromatic regions in the Drosophila genome. Genes Dev 20 2214 2222

23. GunawardaneLS

SaitoK

NishidaKM

MiyoshiK

KawamuraY

2007 A slicer-mediated mechanism for repeat-associated siRNA 5′ end formation in Drosophila. Science 315 1587 1590

24. VaginVV

SigovaA

LiC

SeitzH

GvozdevV

2006 A distinct small RNA pathway silences selfish genetic elements in the germline. Science 313 320 324

25. LiC

VaginVV

LeeS

XuJ

MaS

2009 Collapse of germline piRNAs in the absence of Argonaute3 reveals somatic piRNAs in flies. Cell 137 509 521

26. MaloneCD

BrenneckeJ

DusM

StarkA

McCombieWR

2009 Specialized piRNA pathways act in germline and somatic tissues of the Drosophila ovary. Cell 137 522 535

27. HarrisAN

MacdonaldPM

2001 Aubergine encodes a Drosophila polar granule component required for pole cell formation and related to eIF2C. Development 128 2823 2832

28. CoxDN

ChaoA

LinH

2000 piwi encodes a nucleoplasmic factor whose activity modulates the number and division rate of germline stem cells. Development 127 503 514

29. KlattenhoffC

XiH

LiC

LeeS

XuJ

2009 The Drosophila HP1 homolog Rhino is required for transposon silencing and piRNA production by dual-strand clusters. Cell 138 1137 1149

30. SaitoK

InagakiS

MituyamaT

KawamuraY

OnoY

2009 A regulatory circuit for piwi by the large Maf gene traffic jam in Drosophila. Nature 461 1296 1299

31. DessetS

MeigninC

DastugueB

VauryC

2003 COM, a heterochromatic locus governing the control of independent endogenous retroviruses from Drosophila melanogaster. Genetics 164 501 509

32. Prud'hommeN

GansM

MassonM

TerzianC

BuchetonA

1995 Flamenco, a gene controlling the gypsy retrovirus of Drosophila melanogaster. Genetics 139 697 711

33. LauNC

RobineN

MartinR

ChungWJ

NikiY

2009 Abundant primary piRNAs, endo-siRNAs, and microRNAs in a Drosophila ovary cell line. Genome Res 19 1776 1785

34. DeshpandeG

CalhounG

SchedlP

2005 Drosophila argonaute-2 is required early in embryogenesis for the assembly of centric/centromeric heterochromatin, nuclear division, nuclear migration, and germ-cell formation. Genes Dev 19 1680 1685

35. FagegaltierD

BougeAL

BerryB

PoisotE

SismeiroO

2009 The endogenous siRNA pathway is involved in heterochromatin formation in Drosophila. Proc Natl Acad SciUSA 106 21258 21263

36. Pal-BhadraM

LeibovitchBA

GandhiSG

RaoM

BhadraU

2004 Heterochromatic silencing and HP1 localization in Drosophila are dependent on the RNAi machinery. Science 303 669 672

37. Giles KE, Ghirlando R, Felsenfeld G Maintenance of a constitutive heterochromatin domain in vertebrates by a Dicer-dependent mechanism. Nat Cell Biol 12 94 99; sup pp 91-96

38. RosemanRR

PirrottaV

GeyerPK

1993 The su(Hw) protein insulates expression of the Drosophila melanogaster white gene from chromosomal position-effects. EMBOJ 12 435 442

39. FantiL

DorerDR

BerlocoM

HenikoffS

PimpinelliS

1998 Heterochromatin protein 1 binds transgene arrays. Chromosoma 107 286 292

40. SunFL

HaynesK

SimpsonCL

LeeSD

CollinsL

2004 cis-Acting determinants of heterochromatin formation on Drosophila melanogaster chromosome four. Mol Cell Biol 24 8210 8220

41. ParnellTJ

VieringMM

SkjesolA

HelouC

KuhnEJ

2003 An endogenous suppressor of hairy-wing insulator separates regulatory domains in Drosophila. Proc Natl Acad SciUSA 100 13436 13441

42. MiyoshiK

TsukumoH

NagamiT

SiomiH

SiomiMC

2005 Slicer function of Drosophila Argonautes and its involvement in RISC formation. Genes Dev 19 2837 2848

43. DorerDR

HenikoffS

1994 Expansions of transgene repeats cause heterochromatin formation and gene silencing in Drosophila. Cell 77 993 1002

44. RobertV

Prud'hommeN

KimA

BuchetonA

PelissonA

2001 Characterization of the flamenco region of the Drosophila melanogaster genome. Genetics 158 701 713

45. HaynesKA

CaudyAA

CollinsL

ElginSC

2006 Element 1360 and RNAi components contribute to HP1-dependent silencing of a pericentric reporter. Curr Biol 16 2222 2227

46. KlenovMS

LavrovSA

StolyarenkoAD

RyazanskySS

AravinAA

2007 Repeat-associated siRNAs cause chromatin silencing of retrotransposons in the Drosophila melanogaster germline. Nucleic Acids Res 35 5430 5438

47. PengJC

KarpenGH

2007 H3K9 methylation and RNA interference regulate nucleolar organization and repeated DNA stability. Nat Cell Biol 9 25 35

48. LeiEP

CorcesVG

2006 RNA interference machinery influences the nuclear organization of a chromatin insulator. Nat Genet 38 936 941

49. Pal-BhadraM

BhadraU

BirchlerJA

2002 RNAi related mechanisms affect both transcriptional and posttranscriptional transgene silencing in Drosophila. Mol Cell 9 315 327

50. GrimaudC

BantigniesF

Pal-BhadraM

GhanaP

BhadraU

2006 RNAi components are required for nuclear clustering of Polycomb group response elements. Cell 124 957 971

51. ZofallM

GrewalSI

2006 Swi6/HP1 recruits a JmjC domain protein to facilitate transcription of heterochromatic repeats. Mol Cell 22 681 692

52. ChenES

ZhangK

NicolasE

CamHP

ZofallM

2008 Cell cycle control of centromeric repeat transcription and heterochromatin assembly. Nature 451 734 737

53. KlocA

MartienssenR

2008 RNAi, heterochromatin and the cell cycle. Trends Genet 24 511 517

54. MaisonC

BaillyD

PetersAH

QuivyJP

RocheD

2002 Higher-order structure in pericentric heterochromatin involves a distinct pattern of histone modification and an RNA component. Nat Genet 30 329 334

55. GerasimovaTI

ByrdK

CorcesVG

2000 A chromatin insulator determines the nuclear localization of DNA. Mol Cell 6 1025 1035

56. MongelardF

LabradorM

BaxterEM

GerasimovaTI

CorcesVG

2002 Trans-splicing as a novel mechanism to explain interallelic complementation in Drosophila. Genetics 160 1481 1487

57. LangmeadB

TrapnellC

PopM

SalzbergSL

2009 Ultrafast and memory-efficient alignment of short DNA sequences to the human genome. Genome Biol 10 R25

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