Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

AGO2 silences mobile transposons in the nucleus of quiescent cells

Abstract

Argonaute 2 (AGO2) is a cytoplasmic component of the miRNA pathway, with essential roles in development and disease. Yet little is known about its regulation in vivo. Here we show that in quiescent mouse splenocytes, AGO2 localizes almost exclusively to the nucleus. AGO2 subcellular localization is modulated by the Pi3K–AKT–mTOR pathway, a well-established regulator of quiescence. Signaling through this pathway in proliferating cells promotes AGO2 cytoplasmic accumulation, at least in part by stimulating the expression of TNRC6, an essential AGO2 binding partner in the miRNA pathway. In quiescent cells in which mTOR signaling is low, AGO2 accumulates in the nucleus, where it binds to young mobile transposons co-transcriptionally to repress their expression via its catalytic domain. Our data point to an essential but previously unrecognized nuclear role for AGO2 during quiescence as part of a genome-defense system against young mobile elements and provide evidence of RNA interference in the soma of mammals.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: AGO2 is a nuclear protein in resting mouse splenocytes.
Fig. 2: Regulation of AGO2 subcellular localization.
Fig. 3: AGO2 localization is regulated by the Pi3K–AKT–mTOR pathway.
Fig. 4: Nuclear AGO2 binds young retrotransposable elements.
Fig. 5: AGO2 associates with TE transcripts in quiescent cells.
Fig. 6: AGO2 associates with TE-derived small RNAs in quiescent cells.
Fig. 7: AGO2 represses LINE-1 elements in quiescent cells via its catalytic domain.

Similar content being viewed by others

Data availability

FASTQ and processed files from ChIP–seq and RNA sequencing datasets produced in this study can be found at the Gene Expression Omnibus (GEO) (GSE203049).

ChIP–seq data for H3K9me3 in resting splenic B cells shown in Figure 4 can be downloaded from the GEO (GSE82144). Source data are provided with this paper.

References

  1. Cerutti, H. & Casas-Mollano, J. A. On the origin and functions of RNA-mediated silencing: from protists to man. Curr. Genet. 50, 81–99 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Ozata, D. M. et al. PIWI-interacting RNAs: small RNAs with big functions. Nat. Rev. Genet. 20, 89–108 (2019).

    Article  CAS  PubMed  Google Scholar 

  3. Fire, A. et al. Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature 391, 806–811 (1998).

    Article  CAS  PubMed  Google Scholar 

  4. Hammond, S. M. et al. An RNA-directed nuclease mediates post-transcriptional gene silencing in Drosophila cells. Nature 404, 293–296 (2000).

    Article  CAS  PubMed  Google Scholar 

  5. Bartel, D. P. Metazoan microRNAs. Cell 173, 20–51 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Sala, L., Chandrasekhar, S. & Vidigal, J. A. AGO unchained: canonical and non-canonical roles of Argonaute proteins in mammals. Front. Biosci. 25, 1–42 (2020).

    Article  CAS  Google Scholar 

  7. Stein, P. et al. Essential role for endogenous siRNAs during meiosis in mouse oocytes. PLoS Genet. 11, e1005013 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  8. Meister, G. et al. Identification of novel argonaute-associated proteins. Curr. Biol. 15, 2149–2155 (2005).

    Article  CAS  PubMed  Google Scholar 

  9. Zielezinski, A. & Karlowski, W. M. Early origin and adaptive evolution of the GW182 protein family, the key component of RNA silencing in animals. RNA Biol. 12, 761–770 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  10. Chekulaeva, M. et al. miRNA repression involves GW182-mediated recruitment of CCR4-NOT through conserved W-containing motifs. Nat. Struct. Mol. Biol. 18, 1218–1226 (2011).

    Article  CAS  PubMed  Google Scholar 

  11. Braun, J. E. et al. GW182 proteins directly recruit cytoplasmic deadenylase complexes to miRNA targets. Mol. Cell 44, 120–133 (2011).

    Article  CAS  PubMed  Google Scholar 

  12. Fabian, M. R. et al. miRNA-mediated deadenylation is orchestrated by GW182 through two conserved motifs that interact with CCR4–NOT. Nat. Struct. Mol. Biol. 18, 1211–1217 (2011).

    Article  CAS  PubMed  Google Scholar 

  13. Bhattacharyya, S. N. et al. Relief of microRNA-mediated translational repression in human cells subjected to stress. Cell 125, 1111–1124 (2006).

    Article  CAS  PubMed  Google Scholar 

  14. Ma, J. et al. MicroRNA activity is suppressed in mouse oocytes. Curr. Biol. 20, 265–270 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Suh, N. et al. MicroRNA function is globally suppressed in mouse oocytes and early embryos. Curr. Biol. 20, 271–277 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Bernstein, E. et al. Dicer is essential for mouse development. Nat. Genet. 35, 215–217 (2003).

    Article  CAS  PubMed  Google Scholar 

  17. Wang, Y. et al. DGCR8 is essential for microRNA biogenesis and silencing of embryonic stem cell self-renewal. Nat. Genet. 39, 380–385 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Morita, S. et al. One Argonaute family member, Eif2c2 (Ago2), is essential for development and appears not to be involved in DNA methylation. Genomics 89, 687–696 (2007).

    Article  CAS  PubMed  Google Scholar 

  19. Han, Y. C. et al. An allelic series of miR-17 approximately 92-mutant mice uncovers functional specialization and cooperation among members of a microRNA polycistron. Nat. Genet. 47, 766–775 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Moro, A. et al. MicroRNA-dependent regulation of biomechanical genes establishes tissue stiffness homeostasis. Nat. Cell Biol. 21, 348–358 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Chivukula, R. R. et al. An essential mesenchymal function for miR-143/145 in intestinal epithelial regeneration. Cell 157, 1104–1116 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. de Pontual, L. et al. Germline deletion of the miR-17 approximately 92 cluster causes skeletal and growth defects in humans. Nat. Genet. 43, 1026–1030 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  23. Mencia, A. et al. Mutations in the seed region of human miR-96 are responsible for nonsyndromic progressive hearing loss. Nat. Genet. 41, 609–613 (2009).

    Article  CAS  PubMed  Google Scholar 

  24. Gebert, L. F. R. & MacRae, I. J. Regulation of microRNA function in animals. Nat. Rev. Mol. Cell Biol. 20, 21–37 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Ha, M. & Kim, V. N. Regulation of microRNA biogenesis. Nat. Rev. Mol. Cell Biol. 15, 509–524 (2014).

    Article  CAS  PubMed  Google Scholar 

  26. Zeng, Y. et al. Phosphorylation of Argonaute 2 at serine-387 facilitates its localization to processing bodies. Biochem. J. 413, 429–436 (2008).

    Article  CAS  PubMed  Google Scholar 

  27. Horman, S. R. et al. Akt-mediated phosphorylation of argonaute 2 downregulates cleavage and upregulates translational repression of microRNA targets. Mol. Cell 50, 356–367 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Rudel, S. et al. Phosphorylation of human Argonaute proteins affects small RNA binding. Nucleic Acids Res. 39, 2330–2343 (2011).

    Article  PubMed  Google Scholar 

  29. Bridge, K. S. et al. Argonaute utilization for miRNA silencing is determined by phosphorylation-dependent recruitment of LIM-domain-containing proteins. Cell Rep. 20, 173–187 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. McKenzie, A. J. et al. KRAS–MEK signaling controls Ago2 sorting into exosomes. Cell Rep. 15, 978–987 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Lopez-Orozco, J. et al. Functional analyses of phosphorylation events in human Argonaute 2. RNA 21, 2030–2038 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Shen, J. et al. EGFR modulates microRNA maturation in response to hypoxia through phosphorylation of AGO2. Nature 497, 383–387 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Yang, M. et al. Dephosphorylation of tyrosine 393 in argonaute 2 by protein tyrosine phosphatase 1B regulates gene silencing in oncogenic RAS-induced senescence. Mol. Cell 55, 782–790 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Quevillon Huberdeau, M. et al. Phosphorylation of Argonaute proteins affects mRNA binding and is essential for microRNA-guided gene silencing in vivo. EMBO J. 36, 2088–2106 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Mazumder, A. et al. A transient reversal of miRNA-mediated repression controls macrophage activation. EMBO Rep. 14, 1008–1016 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Golden, R. J. et al. An Argonaute phosphorylation cycle promotes microRNA-mediated silencing. Nature 542, 197–202 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Qi, H. H. et al. Prolyl 4-hydroxylation regulates Argonaute 2 stability. Nature 455, 421–424 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Leung, A. K. et al. Poly(ADP-ribose) regulates stress responses and microRNA activity in the cytoplasm. Mol. Cell 42, 489–499 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Seo, G. J. et al. Reciprocal inhibition between intracellular antiviral signaling and the RNAi machinery in mammalian cells. Cell Host Microbe 14, 435–445 (2013).

    Article  CAS  PubMed  Google Scholar 

  40. van Velthoven, C. T. J. & Rando, T. A. Stem cell quiescence: dynamism, restraint, and cellular idling. Cell Stem Cell 24, 213–225 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  41. Llorens-Bobadilla, E. et al. Single-cell transcriptomics reveals a population of dormant neural stem cells that become activated upon brain injury. Cell Stem Cell 17, 329–340 (2015).

    Article  CAS  PubMed  Google Scholar 

  42. Zhao, M. et al. Megakaryocytes maintain homeostatic quiescence and promote post-injury regeneration of hematopoietic stem cells. Nat. Med. 20, 1321–1326 (2014).

    Article  CAS  PubMed  Google Scholar 

  43. Rodgers, J. T. et al. mTORC1 controls the adaptive transition of quiescent stem cells from G0 to G(Alert). Nature 510, 393–396 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Hamilton, S. E. & Jameson, S. C. CD8 T cell quiescence revisited. Trends Immunol. 33, 224–230 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Glynne, R. et al. B-lymphocyte quiescence, tolerance and activation as viewed by global gene expression profiling on microarrays. Immunol. Rev. 176, 216–246 (2000).

  46. Sprent, J. & Tough, D. F. Lymphocyte life-span and memory. Science 265, 1395–1400 (1994).

    Article  CAS  PubMed  Google Scholar 

  47. Behrens, A. et al. Impact of genomic damage and ageing on stem cell function. Nat. Cell Biol. 16, 201–207 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Burkhalter, M. D., Rudolph, K. L. & Sperka, T. Genome instability of ageing stem cells—induction and defence mechanisms. Ageing Res. Rev. 23, 29–36 (2015).

  49. Burns, K. H. Repetitive DNA in disease. Science 376, 353–354 (2022).

    Article  CAS  PubMed  Google Scholar 

  50. La Rocca, G. et al. In vivo, Argonaute-bound microRNAs exist predominantly in a reservoir of low molecular weight complexes not associated with mRNA. Proc. Natl Acad. Sci. USA 112, 767–772 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  51. Morris, K. V. et al. Small interfering RNA-induced transcriptional gene silencing in human cells. Science 305, 1289–1292 (2004).

    Article  CAS  PubMed  Google Scholar 

  52. Robb, G. B. et al. Specific and potent RNAi in the nucleus of human cells. Nat. Struct. Mol. Biol. 12, 133–137 (2005).

    Article  CAS  PubMed  Google Scholar 

  53. Weinberg, M. S. et al. The antisense strand of small interfering RNAs directs histone methylation and transcriptional gene silencing in human cells. RNA 12, 256–262 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Janowski, B. A. et al. Involvement of AGO1 and AGO2 in mammalian transcriptional silencing. Nat. Struct. Mol. Biol. 13, 787–792 (2006).

    Article  CAS  PubMed  Google Scholar 

  55. Rudel, S. et al. A multifunctional human Argonaute2-specific monoclonal antibody. RNA 14, 1244–1253 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  56. Weinmann, L. et al. Importin 8 is a gene silencing factor that targets argonaute proteins to distinct mRNAs. Cell 136, 496–507 (2009).

    Article  CAS  PubMed  Google Scholar 

  57. Chu, Y. et al. Involvement of argonaute proteins in gene silencing and activation by RNAs complementary to a non-coding transcript at the progesterone receptor promoter. Nucleic Acids Res. 38, 7736–7748 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Gagnon, K. T. et al. RNAi factors are present and active in human cell nuclei. Cell Rep. 6, 211–221 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Zamudio, J. R., Kelly, T. J. & Sharp, P. A. Argonaute-bound small RNAs from promoter-proximal RNA polymerase II. Cell 156, 920–934 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Sarshad, A. A. et al. Argonaute–miRNA complexes silence target mRNAs in the nucleus of mammalian stem cells. Mol. Cell 71, 1040–1050 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  61. Kieffer-Kwon, K. R. et al. Myc regulates chromatin decompaction and nuclear architecture during B cell activation. Mol. Cell 67, 566–578 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Trickett, A. & Kwan, Y. L. T cell stimulation and expansion using anti-CD3/CD28 beads. J. Immunol. Methods 275, 251–255 (2003).

    Article  CAS  PubMed  Google Scholar 

  63. Coller, H. A., Sang, L. & Roberts, J. M. A new description of cellular quiescence. PLoS Biol. 4, e83 (2006).

    Article  PubMed  PubMed Central  Google Scholar 

  64. Augenlicht, L. H. & Baserga, R. Changes in the G0 state of WI-38 fibroblasts at different times after confluence. Exp. Cell. Res. 89, 255–262 (1974).

    Article  CAS  PubMed  Google Scholar 

  65. Valcourt, J. R. et al. Staying alive: metabolic adaptations to quiescence. Cell Cycle 11, 1680–1696 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Oldham, S. et al. Genetic and biochemical characterization of dTOR, the Drosophila homolog of the target of rapamycin. Genes Dev 14, 2689–2694 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. Zhang, H. et al. Regulation of cellular growth by the Drosophila target of rapamycin dTOR. Genes Dev. 14, 2712–2724 (2000).

  68. Olejniczak, S. H. et al. Coordinated regulation of Cap-dependent translation and microRNA function by convergent signaling pathways. Mol. Cell. Biol. 36, 2360–2373 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Iwasaki, Y. W. et al. Global microRNA elevation by inducible Exportin 5 regulates cell cycle entry. RNA 19, 490–497 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. Olejniczak, S. H. et al. Long-lived microRNA–Argonaute complexes in quiescent cells can be activated to regulate mitogenic responses. Proc. Natl Acad. Sci. USA 110, 157–162 (2013).

    Article  CAS  PubMed  Google Scholar 

  71. Schraivogel, D. et al. Importin-beta facilitates nuclear import of human GW proteins and balances cytoplasmic gene silencing protein levels. Nucleic Acids Res. 43, 7447–7461 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Nishi, K. et al. Human TNRC6A is an Argonaute-navigator protein for microRNA-mediated gene silencing in the nucleus. RNA 19, 17–35 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  73. Marinov, G. K. et al. Pitfalls of mapping high-throughput sequencing data to repetitive sequences: Piwi’s genomic targets still not identified. Dev. Cell 32, 765–771 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Feng, J. et al. Identifying ChIP–seq enrichment using MACS. Nat. Protoc. 7, 1728–1740 (2012).

    Article  CAS  PubMed  Google Scholar 

  75. Lahmy, S. et al. Evidence for ARGONAUTE4-DNA interactions in RNA-directed DNA methylation in plants. Genes Dev. 30, 2565–2570 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Noma, K. et al. RITS acts in cis to promote RNA interference-mediated transcriptional and post-transcriptional silencing. Nat. Genet. 36, 1174–1180 (2004).

    Article  CAS  PubMed  Google Scholar 

  77. Liu, C. et al. Arabidopsis ARGONAUTE 1 binds chromatin to promote gene transcription in response to hormones and stresses. Dev. Cell 44, 348–361 (2018).

    Article  PubMed  Google Scholar 

  78. Cernilogar, F. M. et al. Chromatin-associated RNA interference components contribute to transcriptional regulation in Drosophila. Nature 480, 391–395 (2011).

  79. Claycomb, J. M. et al. The Argonaute CSR-1 and its 22G-RNA cofactors are required for holocentric chromosome segregation. Cell 139, 123–134 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Sookdeo, A. et al. Revisiting the evolution of mouse LINE-1 in the genomic era. Mob. DNA 4, 3 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. Mouse Genome Sequencing Consortium et al. Initial sequencing and comparative analysis of the mouse genome. Nature 420, 520–562 (2002).

  82. Ostertag, E. M. & Kazazian, H. H. Jr. Biology of mammalian L1 retrotransposons. Annu. Rev. Genet. 35, 501–538 (2001).

    Article  CAS  PubMed  Google Scholar 

  83. Zamore, P. D. et al. RNAi: double-stranded RNA directs the ATP-dependent cleavage of mRNA at 21 to 23 nucleotide intervals. Cell 101, 25–33 (2000).

    Article  CAS  PubMed  Google Scholar 

  84. Elbashir, S. M. et al. Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature 411, 494–498 (2001).

    Article  CAS  PubMed  Google Scholar 

  85. Becker, W. R. et al. High-throughput analysis reveals rules for target RNA binding and cleavage by AGO2. Mol. Cell 75, 741–755 (2019).

  86. Meister, G. et al. Human Argonaute2 mediates RNA cleavage targeted by miRNAs and siRNAs. Mol. Cell 15, 185–197 (2004).

    Article  CAS  PubMed  Google Scholar 

  87. Liu, J. et al. Argonaute2 is the catalytic engine of mammalian RNAi. Science 305, 1437–1441 (2004).

    Article  CAS  PubMed  Google Scholar 

  88. Rivas, F. V. et al. Purified Argonaute2 and an siRNA form recombinant human RISC. Nat. Struct. Mol. Biol. 12, 340–349 (2005).

    Article  CAS  PubMed  Google Scholar 

  89. Cheloufi, S. et al. A dicer-independent miRNA biogenesis pathway that requires Ago catalysis. Nature 465, 584–589 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  90. Reuter, M. et al. Miwi catalysis is required for piRNA amplification-independent LINE1 transposon silencing. Nature 480, 264–267 (2011).

    Article  CAS  PubMed  Google Scholar 

  91. Aravin, A. A. et al. Developmentally regulated piRNA clusters implicate MILI in transposon control. Science 316, 744–747 (2007).

    Article  CAS  PubMed  Google Scholar 

  92. Loubalova, Z. et al. Formation of spermatogonia and fertile oocytes in golden hamsters requires piRNAs. Nat. Cell Biol. 23, 992–1001 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  93. Murchison, E. P. et al. Critical roles for Dicer in the female germline. Genes Dev. 21, 682–693 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  94. Volpe, T. A. et al. Regulation of heterochromatic silencing and histone H3 lysine-9 methylation by RNAi. Science 297, 1833–1837 (2002).

    Article  CAS  PubMed  Google Scholar 

  95. Yamanaka, S. et al. RNAi triggered by specialized machinery silences developmental genes and retrotransposons. Nature 493, 557–560 (2013).

    Article  CAS  PubMed  Google Scholar 

  96. Nazer et al. Seeking the truth behind the myth: Argonaute tales from ‘nuclearland’. Mol. Cell 82, 503–513 (2022).

    Article  CAS  PubMed  Google Scholar 

  97. Till, S. et al. A conserved motif in Argonaute-interacting proteins mediates functional interactions through the Argonaute PIWI domain. Nat. Struct. Mol. Biol. 14, 897–903 (2007).

    Article  CAS  PubMed  Google Scholar 

  98. Ji, L. & Chen, X. Regulation of small RNA stability: methylation and beyond. Cell Res. 22, 624–636 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  99. Demeter, T. et al. Main constraints for RNAi induced by expressed long dsRNA in mouse cells. Life Sci. Alliance 2, e201800289 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  100. Lee, Y. Y., Kim, H. & Kim, V. N. Sequence determinant of small RNA production by DICER. Nature 615, 323–330 (2023).

    Article  CAS  PubMed  Google Scholar 

  101. Roche, B., Arcangioli, B. & Martienssen, R. A. RNA interference is essential for cellular quiescence. Science 354, aah5651 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  102. Kouzine, F. et al. Global regulation of promoter melting in naive lymphocytes. Cell 153, 988–999 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  103. Nie, Z. et al. c-Myc is a universal amplifier of expressed genes in lymphocytes and embryonic stem cells. Cell 151, 68–79 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  104. Marasca, F. et al. LINE1 are spliced in non-canonical transcript variants to regulate T cell quiescence and exhaustion. Nat. Genet. 54, 180–193 (2022).

    Article  CAS  PubMed  Google Scholar 

  105. O’Carroll, D. et al. A Slicer-independent role for Argonaute 2 in hematopoiesis and the microRNA pathway. Genes Dev. 21, 1999–2004 (2007).

    Article  PubMed  PubMed Central  Google Scholar 

  106. Ventura, A. et al. Restoration of p53 function leads to tumour regression in vivo. Nature 445, 661–665 (2007).

    Article  CAS  PubMed  Google Scholar 

  107. Kieffer-Kwon, K. R. et al. Interactome maps of mouse gene regulatory domains reveal basic principles of transcriptional regulation. Cell 155, 1507–1520 (2013).

    Article  CAS  PubMed  Google Scholar 

  108. Zhao, J. J. et al. Human mammary epithelial cell transformation through the activation of phosphatidylinositol 3-kinase. Cancer Cell 3, 483–495 (2003).

    Article  CAS  PubMed  Google Scholar 

  109. Bredemeyer, A. L. et al. ATM stabilizes DNA double-strand-break complexes during V(D)J recombination. Nature 442, 466–470 (2006).

    Article  CAS  PubMed  Google Scholar 

  110. Muljo, S. A. & Schlissel, M. S. A small molecule Abl kinase inhibitor induces differentiation of Abelson virus-transformed pre-B cell lines. Nat. Immunol. 4, 31–37 (2003).

    Article  CAS  PubMed  Google Scholar 

  111. Chen, B. R. et al. LIN37–DREAM prevents DNA end resection and homologous recombination at DNA double-strand breaks in quiescent cells. eLife 10, e68466 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  112. Girish, V. & Vijayalakshmi, A. Affordable image analysis using NIH Image/ImageJ. Indian J. Cancer 41, 47 (2004).

    Article  CAS  PubMed  Google Scholar 

  113. Sun, L. & Fang, J. Macromolecular crowding effect is critical for maintaining SIRT1’s nuclear localization in cancer cells. Cell Cycle 15, 2647–2655 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  114. Bodak, M. et al. Dicer, a new regulator of pluripotency exit and LINE-1 elements in mouse embryonic stem cells. FEBS Open Bio. 7, 204–220 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  115. Kigami, D. et al. MuERV-L is one of the earliest transcribed genes in mouse one-cell embryos. Biol. Reprod. 68, 651–654 (2003).

    Article  CAS  PubMed  Google Scholar 

  116. Jeong, H. H. et al. An ultra-fast and scalable quantification pipeline for transposable elements from next generation sequencing data. Pac. Symp. Biocomput. 23, 168–179 (2018).

    PubMed  Google Scholar 

  117. Martin, M. Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet J. 17, 10–12 (2011).

    Article  Google Scholar 

  118. Smith, T., Heger, A. & Sudbery, I. UMI-tools: modeling sequencing errors in unique molecular identifiers to improve quantification accuracy. Genome Res. 27, 491–499 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  119. Teissandier, A. et al. Tools and best practices for retrotransposon analysis using high-throughput sequencing data. Mob. DNA 10, 52 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  120. Danecek, P. et al. Twelve years of SAMtools and BCFtools. Gigascience 10, giab008 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  121. Langmead, B. & Salzberg, S. L. Fast gapped-read alignment with Bowtie 2. Nat. Methods 9, 357–359 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  122. Quinlan, A. R. & Hall, I. M. BEDTools: a flexible suite of utilities for comparing genomic features. Bioinformatics 26, 841–842 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  123. Amemiya, H. M., Kundaje, A. & Boyle, A. P. The ENCODE blacklist: identification of problematic regions of the genome. Sci. Rep. 9, 9354 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  124. The ENCODE Project Consortium. An integrated encyclopedia of DNA elements in the human genome. Nature 489, 57–74 (2012).

  125. Kapusta, A. et al. Transposable elements are major contributors to the origin, diversification, and regulation of vertebrate long noncoding RNAs. PLoS Genet. 9, e1003470 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  126. Trizzino, M., Kapusta, A. & Brown, C. D. Transposable elements generate regulatory novelty in a tissue-specific fashion. BMC Genomics 19, 468 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  127. Smit, A., Hubley, R. & Green, P. RepeatMasker Open-4.0. (2013–2015); http://www.repeatmasker.org

  128. Ramirez, F. et al. deepTools2: a next generation web server for deep-sequencing data analysis. Nucleic Acids Res. 44, W160–W165 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  129. Robinson, J. T. et al. Integrative genomics viewer. Nat. Biotechnol. 29, 24–26 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  130. R Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2018).

Download references

Acknowledgements

We thank all members of the Vidigal and Batista labs for discussions and comments on this work. We also thank P. P. Rocha, S. Chakraborty, and J. Thompson for help and advice on ChIP–seq experiments. We thank the NCI’s Laboratory Animal Sciences Program, in particular D. Gallardo and M. Figueroa, for expert mouse care and help maintaining the mouse colonies. We also thank the NCI’s molecular histopathology core, especially T. Morgan, J. Mata, and B. Karim. This work utilized the computational resources of the NIH HPC Biowulf cluster (hpc.nih.gov). R.L.C. is supported by the NIH PRAT fellowship FI2GM142571-01. This work was supported by the Intramural Research Program of the National Institutes of Health through the Center for Cancer Research, National Cancer Institute, project 1ZIABC011810-02 (J.A.V.), and was partially funded by contract number HHSN261201500003I (R.C., P.A.).

Author information

Authors and Affiliations

Authors

Contributions

L.S. and J.A.V. conceived the project with input from G.L.R. L.S., M. Kumar, M.P., and J.A.V. performed experiments and analysis. S.C., R.C., M. Kruhlak, and P.A. helped with experiments. J.A.V. supervised the project. R.L.C. and T.S.M. provided expertise in the analysis over TE elements. L.S. and J.A.V. wrote the manuscript with input from all authors.

Corresponding author

Correspondence to Joana A. Vidigal.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Structural & Molecular Biology thanks the anonymous reviewers for their contribution to the peer review of this work. Peer reviewer reports are available. Primary Handling Editors: Carolina Perdigoto and Dimitris Typas, in collaboration with the Nature Structural & Molecular Biology team.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Ago2HA/HA mice are phenotypically normal and have intact Ago2 functions.

(a) Targeting strategy. An 2xHA tag and short linker sequence were introduced directly downstream of start codon maintaining 5′UTR and promoter sequences intact. Position of the first exon (1) and length of homology arms are shown. (b) Western blot to MEFs obtained from heterozygous intercrosses. (c) Luciferase assay in MEFs showing intact repression of miRNA (orange) and AGO2 cleavage (red) reporters. Values represent mean of two biological replicates. Error bars represent standard deviation. p-values were calculated using a one-sided t-test. (d) Expected and observed numbers of genotypes obtained from heterozygous intercrosses at weaning. p-value was calculated with a Chi-square test. (e) Weigh of littermate animals at weaning (males: 14 wild-type, 25 heterozygous, 12 homozygous; females: 11 wild-type, 30 heterozygous, 9 homozygous). Data are presented as mean values +/− SD. p-values were calculated using a one-sided t-test. (f) Hematoxylin & Eosin-stained sections of tissues isolated from Ago2HA/HA animals and Ago2+/+ controls showing intact tissue morphology in homozygous animals.

Source data

Extended Data Fig. 2 AGO2 localization in quiescent versus proliferating cells.

(a) Ex-vivo splenocyte activation leads to a significant increase in cell size. (b) Splenocyte activation has minimal impact in relative sizes of nuclear and cytoplasmic compartments. (c) Percentage of total HA signal that is localized to the nucleus in activated B and T splenocytes. (d) Percentage of total HA signal that is localized to the nucleus in primary MEFs grown in complete media (10% serum; Fed), serum starved for 8 days (0.1% serum; Starved, Str), and refed for 24 h following an 8-day serum starvation (Refed, Ref). For all boxplots, each dot represents a cell. Boxplots show minimum, maximum, median, first, and third quartiles. Median value (x) and number (n) of cells analyzed per condition are shown. Values are based on 93 resting and 154 activated B cells or 141 resting and 69 activated T cells collected from two independent experiments. P values were calculated with a two-sided Wilcoxon test.

Source data

Extended Data Fig. 3 AGO2 is regulated by the Pi3K-AKT-mTOR pathway at least in part through levels of TNRC6.

(a) Chemical inhibition of Pi3K-AKT-mTOR and MEK-ERK pathways in immortalized MEFs. A schematic representation of the Pi3K pathway and the drugs used for its inhibition is shown on the left (Pi3Ki, LY294002; AKTi, MK2206; mTORi, Torin1). (b) Top, schematic representation of the MEK-ERK mitogenic pathway and the drug used to inhibit is (MEKi, PD032590). Bottom, western blot showing activity of the pathway in resting (Res) and activated (Act) splenocytes. (c) Western blot showing AGO2 and TNRC6 levels in primary MEFs cultured in complete media (Fed), serum starved (Str), or starved and refeed for 24 h (Ref). (d) TNRC6 levels but not AGO2 levels are downregulated by Pi3K pathway inhibitors. (e) qPCR to Tnrc6 family members following the delivery of indicated siRNAs to immortalized MEFs. Data are presented as mean values of three independent experiments +/− SD. p-values were calculated using a two-sided Wilcoxon test. (f) Western blot to TNRC6 following downregulation of all three isoforms.

Source data

Extended Data Fig. 4 AGO2HA associates with chromatin in an RNA-dependent manner.

(a) Western blot showing undetectable expression of AGO1 and AGO3 in primary mouse B cells. Lysates from two biological independent mouse embryonic fibroblast lines (MEF1 and MEF2) were used as control. Res., resting cells; Act., activated cells. (b) Schematic representation of experimental procedure. RNase treatment was performed on nuclear extracts before separating nuclear soluble (NS) and chromatin enriched (Chr) fractions. As control, samples from wild-type or tagged animals were processed in parallel but omitting the RNA endonucleases (mock). (c) Western blot to sub-cellular fractions following RNase treatment of nuclear extracts shown in (B).

Source data

Extended Data Fig. 5 Enrichment of AGO2HA peaks over TE elements.

(a) MACS-called peaks overlap almost exclusively with repetitive elements. (b) Significance values for all repetitive elements that are significantly enriched in high-confidence AGO2 peaks. (c) Mean expected overlaps (calculated from 1000 random shuffles) compared to the observed overlaps over significantly enriched LINE elements. (d) Mean expected overlaps (calculated from 1000 random shuffles) compared to the observed overlaps over significantly enriched ERV elements.

Source data

Extended Data Fig. 6 AGO2HA is enriched at young LINE and ERV retrotransposons.

(a) Example genome browser view showing enrichment of AGO2HA over the consensus sequence of young LINE-1 elements (blue) or young ERV elements (green). For each bin, enrichment was calculated as the log2 value of the ratio between the reads per million (RPM) of AGO2HA samples (HARPM) and those of the wild-type samples (WTRPM). As a result, regions where AGO2HA is enriched are represented by positive values, and those where AGO2HA is depleted are represented by negative values. (b) Example genome browser view over a young L1 element for the indicated ChIP-seq data. Individual biological replicates are shown in light blue (Ago2HA/HA samples) or light grey (Ago2+/+ samples). Tracks with replicate data merged are show in dark blue or dark grey. Notice the enrichment of ChIP-seq reads in Ago2HA/HA samples over the LINE-1 element compared to control Ago2+/+ samples when all reads (uniquely mapping as well as multimapping) are considered. In contrast, because of its repetitive nature, reads mapping uniquely to this element are mostly absent. Notice also how paired-end sequencing (PE seq) which increases the length of the reads compared to single-read (SR) allows the identification of a peak for uniquely mapping reads at the border between the L1 element and the uniquely mappable region of the genome in the Ago2HA/HA but not the Ago2+/+ ChIP confirming that enrichment is not an artefact of multimapping reads. A detailed view of this peak as well as the underlying reads is show in (c).

Extended Data Fig. 7 ChIP-seq analysis to AGO2HA in quiescent B cells.

(a) Correlation of normalized read counts across biological replicates mapping to transposable elements (TE) following ChIP-seq with an antibody against HA in Ago2+/+ (left) and Ago2HA/HA (right). Each dot represents a distinct TE. Repeats enriched in Ago2HA/HA compared to Ago2+/+ ChIP-seq are labeled in red. (b) As in (A) but comparing Ago2HA/HA and Ago2+/+ normalized read counts for replicate 1 (left) and 2 (right). (c) Cumulative Distribution Fraction plot for log2(TPM + 1) expression values of repeats with (red) or without (grey) AGO2HA enrichment in ChIP-seq data. TPM, transcript per million. p-value was calculated with a two-sided Kolmogorov–Smirnov test.

Extended Data Fig. 8 Small RNAs associated with AGO2 in resting and activated cells.

(a) Representative western blot of fractions obtained following AGO2 pulldowns. Sup., supernatant; Inp., input; IP, immunoprecipitation. 1% of each fraction was loaded on the blot. Inputs from wild-type controls are shown as a control for the specificity of the antibody. (b) Composition of small RNA reads that map to annotated ncRNA loci in input (left) and IP samples (right) according to length distribution. Reads were normalized to total number of mapped reads. (c) Enrichment of miRNAs in AGO2 pulldowns in activated (Act.) and resting (Res.) primary B cells. (d) Number of reads mapping to miRNAs or TEs following pulldowns of AGO2 in resting B cells. The y-axis represents reads per million (RPM) of 20-24 nucleotide long RNAs. Data shown in C-D represents the average between two biological replicates.

Source data

Extended Data Fig. 9 Loss of Ago2 catalytic competence does not result in overt changes in H3K9me3.

(a) Western blot to AGO2 following CRE-mediated locus recombination. (b) Left, representation of the outcome of the recombination experiment. Right, relative expression levels of IAP and MERVL following conditional loss of AGO2 in resting B cells. Data are presented as mean of biological duplicates +/− SD. p values were calculated with a two-sided t-test. (c) Profile plots showing normalized read counts for H3K9me3 ChIP-seq over two example young L1 repeats following CRE-mediated recombination of Ago2flx/+ and Ago2flx/ADH in resting B cells and Ago2+/+ controls. (d) H3K9me3 ChIP signal depth over consensus repeat sequences. (e) Enrichment for H3K9me3 (calculated as log2 of the ratio between ChIP and input) for repeats of the L1MdA (top), L1MdTf, and L1MdGf (bottom) young L1 families following CRE-mediated recombination of Ago2flx/+ and Ago2flx/ADH in resting B cells and Ago2+/+ controls. Boxplots show minimum, maximum, median, first, and third quartiles from two biological replicates whose individual values are represented by a dot.

Source data

Extended Data Fig. 10 Overlap of AGO2HA and histone post-translational modifications.

Representative SIM super-resolution optical mid-sections of co-immunofluorescence for HA (green) and the indicated histone marks (red). Scale bar: 1 µm.

Supplementary information

Supplementary Information

Supplementary Figs. 1–3, Table 1, Note 1 and Methods.

Reporting Summary

Peer Review File

Source data

Source Data Figs. 1 and 2 and Extended Data Fig. 2

Statistical source data for Figs. 1b and 2c,e, and Extended Data Fig. 2d.

Source Data Figs. 1 and 2

Unprocessed Western Blots for Figs. 1c and 2d.

Source Data Fig. 3

Statistical source data for Fig. 3b,d.

Source Data Fig. 3

Unprocessed Western blots for Fig. 3a,c.

Source Data Fig. 4

Unprocessed Western blots for Fig. 4a.

Source Data Fig. 5

Statistical source data for Fig. 5c.

Source Data Fig. 7

Statistical source data for Fig. 7.

Source Data Extended Data Fig. 1

Statistical source data for Extended Data Fig. 1c,e.

Source Data Extended Data Fig. 1

Unprocessed Western blots for Extended Data Fig. 1b.

Source Data Extended Data Fig. 3

Unprocessed Western blots for Extended Data Fig. 3a–d,f.

Source Data Extended Data Fig. 4

Unprocessed Western blots for Extended Data Fig. 4a, c.

Source Data Extended Data Fig. 5

Statistical source data for Extended Data Fig. 5b–d.

Source Data Extended Data Fig. 8

Unprocessed Western blots for Extended Data Fig. 8a.

Source Data Extended Data Fig. 9

Statistical source data for Extended Data Fig. 9b.

Source Data Extended Data Fig. 9

Unprocessed Western blots for Extended Data Fig. 9a.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sala, L., Kumar, M., Prajapat, M. et al. AGO2 silences mobile transposons in the nucleus of quiescent cells. Nat Struct Mol Biol 30, 1985–1995 (2023). https://doi.org/10.1038/s41594-023-01151-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41594-023-01151-z

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing