Article | Published:

Tau-driven 26S proteasome impairment and cognitive dysfunction can be prevented early in disease by activating cAMP-PKA signaling

Nature Medicine volume 22, pages 4653 (2016) | Download Citation

Abstract

The ubiquitin proteasome system (UPS) degrades misfolded proteins including those implicated in neurodegenerative diseases. We investigated the effects of tau accumulation on proteasome function in a mouse model of tauopathy and in a cross to a UPS reporter mouse (line Ub-G76V-GFP). Accumulation of insoluble tau was associated with a decrease in the peptidase activity of brain 26S proteasomes, higher levels of ubiquitinated proteins and undegraded Ub-G76V-GFP. 26S proteasomes from mice with tauopathy were physically associated with tau and were less active in hydrolyzing ubiquitinated proteins, small peptides and ATP. 26S proteasomes from normal mice incubated with recombinant oligomers or fibrils also showed lower hydrolyzing capacity in the same assays, implicating tau as a proteotoxin. Administration of an agent that activates cAMP–protein kinase A (PKA) signaling led to attenuation of proteasome dysfunction, probably through proteasome subunit phosphorylation. In vivo, this led to lower levels of aggregated tau and improvements in cognitive performance.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    Protein degradation and protection against misfolded or damaged proteins. Nature 426, 895–899 (2003).

  2. 2.

    Recognition and processing of ubiquitin-protein conjugates by the proteasome. Annu. Rev. Biochem. 78, 477–513 (2009).

  3. 3.

    et al. Complete subunit architecture of the proteasome regulatory particle. Nature 482, 186–191 (2012).

  4. 4.

    et al. Near-atomic resolution structural model of the yeast 26S proteasome. Proc. Natl. Acad. Sci. USA 109, 14870–14875 (2012).

  5. 5.

    et al. PKA rapidly enhances proteasome assembly and activity in in vivo canine hearts. J. Mol. Cell. Cardiol. 46, 452–462 (2009).

  6. 6.

    et al. Proteasome function is regulated by cyclic AMP-dependent protein kinase through phosphorylation of Rpt6. J. Biol. Chem. 282, 22460–22471 (2007).

  7. 7.

    , & cAMP stimulates the ubiquitin/proteasome pathway in rat spinal cord neurons. Neurosci. Lett. 527, 126–131 (2012).

  8. 8.

    , & Impaired proteasome function in Alzheimer's disease. J. Neurochem. 75, 436–439 (2000).

  9. 9.

    et al. Alzheimer disease-specific conformation of hyperphosphorylated paired helical filament-Tau is polyubiquitinated through Lys-48, Lys-11, and Lys-6 ubiquitin conjugation. J. Biol. Chem. 281, 10825–10838 (2006).

  10. 10.

    , & Proteomic analysis of protein phosphorylation and ubiquitination in Alzheimer's disease. Methods Mol. Biol. 566, 109–121 (2009).

  11. 11.

    et al. Tau post-translational modifications in wild-type and human amyloid precursor protein transgenic mice. Nat. Neurosci. 18, 1183–1189 (2015).

  12. 12.

    et al. The synaptic accumulation of hyperphosphorylated tau oligomers in Alzheimer disease is associated with dysfunction of the ubiquitin-proteasome system. Am. J. Pathol. 181, 1426–1435 (2012).

  13. 13.

    , & Tau degradation: the ubiquitin-proteasome system versus the autophagy-lysosome system. Prog. Neurobiol. 105, 49–59 (2013).

  14. 14.

    et al. Proteasomal degradation of tau protein. J. Neurochem. 83, 176–185 (2002).

  15. 15.

    et al. Direct cellular delivery of human proteasomes to delay tau aggregation. Nat. Commun. 5, 5633 (2014).

  16. 16.

    , , & Proteasome inhibition by paired helical filament-tau in brains of patients with Alzheimer's disease. J. Neurochem. 85, 115–122 (2003).

  17. 17.

    , & Coordination between proteasome impairment and caspase activation leading to TAU pathology: neuroprotection by cAMP. Cell Death Dis. 3, e326 (2012).

  18. 18.

    et al. Tau suppression in a neurodegenerative mouse model improves memory function. Science 309, 476–481 (2005).

  19. 19.

    & Affinity purification of mammalian 26S proteasomes using an ubiquitin-like domain. Methods Mol. Biol. 832, 423–432 (2012).

  20. 20.

    , , & Ubiquitinated proteins activate the proteasomal ATPases by binding to Usp14 or Uch37 homologs. J. Biol. Chem. 288, 7781–7790 (2013).

  21. 21.

    , , & Selective degradation of ubiquitinated Sic1 by purified 26S proteasome yields active S phase cyclin-Cdk. Mol. Cell 8, 439–448 (2001).

  22. 22.

    & Proteasomal AAA-ATPases: structure and function. Biochim. Biophys. Acta 1823, 67–82 (2012).

  23. 23.

    , , , & ATP binds to proteasomal ATPases in pairs with distinct functional effects, implying an ordered reaction cycle. Cell 144, 526–538 (2011).

  24. 24.

    , , & A transgenic mouse model of the ubiquitin/proteasome system. Nat. Biotechnol. 21, 897–902 (2003).

  25. 25.

    et al. Neurofibrillary tangles, amyotrophy and progressive motor disturbance in mice expressing mutant (P301L) tau protein. Nat. Genet. 25, 402–405 (2000).

  26. 26.

    et al. Misfolded PrP impairs the UPS by interaction with the 20S proteasome and inhibition of substrate entry. EMBO J. 30, 3065–3077 (2011).

  27. 27.

    et al. Small misfolded Tau species are internalized via bulk endocytosis and anterogradely and retrogradely transported in neurons. J. Biol. Chem. 288, 1856–1870 (2013).

  28. 28.

    et al. Resveratrol ameliorates aging-related metabolic phenotypes by inhibiting cAMP phosphodiesterases. Cell 148, 421–433 (2012).

  29. 29.

    et al. Protein kinase A phosphorylation of tau-serine 214 reorganizes microtubules and disrupts the endothelial cell barrier. Am. J. Physiol. Lung Cell. Mol. Physiol. 299, L493–L501 (2010).

  30. 30.

    , , , & Phosphorylation that detaches tau protein from microtubules (Ser262, Ser214) also protects it against aggregation into Alzheimer paired helical filaments. Biochemistry 38, 3549–3558 (1999).

  31. 31.

    et al. Phosphorylation of tau at Ser214 mediates its interaction with 14-3-3 protein: implications for the mechanism of tau aggregation. J. Neurochem. 108, 33–43 (2009).

  32. 32.

    , & cAMP-induced phosphorylation of 26S proteasomes on Rpn6/PSMD11 enhances their activity and the degradation of misfolded proteins. Proc. Natl. Acad. Sci. USA (in the press).

  33. 33.

    & Dynamics of the degradation of ubiquitinated proteins by proteasomes and autophagy: association with sequestosome 1/p62. J. Biol. Chem. 286, 22426–22440 (2011).

  34. 34.

    et al. Regulation of the autophagy protein LC3 by phosphorylation. J. Cell Biol. 190, 533–539 (2010).

  35. 35.

    , & The molecular and systems biology of memory. Cell 157, 163–186 (2014).

  36. 36.

    , & ATP-dependent steps in the binding of ubiquitin conjugates to the 26S proteasome that commit to degradation. Mol. Cell 40, 671–681 (2010).

  37. 37.

    , & Keeping proteasomes under control–a role for phosphorylation in the nucleus. Proc. Natl. Acad. Sci. USA 108, 18573–18574 (2011).

  38. 38.

    et al. Enhancement of proteasome activity by a small-molecule inhibitor of USP14. Nature 467, 179–184 (2010).

  39. 39.

    et al. Regulation of feedback between protein kinase A and the proteasome system worsens Huntington's disease. Mol. Cell. Biol. 33, 1073–1084 (2013).

  40. 40.

    , & The ATP costs and time required to degrade ubiquitinated proteins by the 26 S proteasome. J. Biol. Chem. 288, 29215–29222 (2013).

  41. 41.

    et al. Trans-synaptic spread of tau pathology in vivo. PLoS One 7, e31302 (2012).

  42. 42.

    et al. Propagation of tau pathology in a model of early Alzheimer's disease. Neuron 73, 685–697 (2012).

  43. 43.

    , , & Organotypic slice cultures from transgenic mice as disease model systems. J. Mol. Neurosci. 19, 317–320 (2002).

  44. 44.

    Developments of a water-maze procedure for studying spatial learning in the rat. J. Neurosci. Methods 11, 47–60 (1984).

  45. 45.

    , , & Assessment of proteasome impairment and accumulation/aggregation of ubiquitinated proteins in neuronal cultures. Methods Mol. Biol. 793, 273–296 (2011).

  46. 46.

    , & Preparation of ubiquitinated substrates by the PY motif-insertion method for monitoring 26S proteasome activity. Methods Enzymol. 399, 215–227 (2005).

  47. 47.

    , & Ubiquitinated proteins activate the proteasome by binding to Usp14/Ubp6, which causes 20S gate opening. Mol. Cell 36, 794–804 (2009).

  48. 48.

    , & The synthesis and proteasomal degradation of a model substrate Ub5DHFR. Methods Enzymol. 398, 379–390 (2005).

Download references

Acknowledgements

We thank J. Lewis and K. Ashe for providing rTg4510 and JNPL3 mice and P. Davies for the generous gift of tau antibodies. We thank L. Liu for assisting with mice perfusion. This work was supported by grants from the US National Institute of Neurological Disorders and Stroke NS074593 (K.E.D.), CurePSP Foundation (N.M.), the US National Institute of General Medical Sciences GM051923 (to A.L.G.), the Fidelity Biosciences Research Initiative (A.L.G.) and the Multiple Myeloma Research Foundation (N.V.K.).

Author information

Affiliations

  1. Department of Pathology and Cell Biology, Taub Institute for Alzheimer's Disease Research, Columbia University, New York, New York, USA.

    • Natura Myeku
    • , Catherine L Clelland
    • , Sheina Emrani
    • , Wai Haung Yu
    •  & Karen E Duff
  2. Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.

    • Nikolay V Kukushkin
    •  & Alfred L Goldberg
  3. Division of Integrative Neuroscience in the Department of Psychiatry, New York State Psychiatric Institute, New York, New York, USA.

    • Karen E Duff

Authors

  1. Search for Natura Myeku in:

  2. Search for Catherine L Clelland in:

  3. Search for Sheina Emrani in:

  4. Search for Nikolay V Kukushkin in:

  5. Search for Wai Haung Yu in:

  6. Search for Alfred L Goldberg in:

  7. Search for Karen E Duff in:

Contributions

N.M. performed all experiments except for the degradation assay of ubiquitinated proteins. C.L.C. performed STATA analyses for behavioral studies; S.E. assisted with IHC and water maze experiments; N.V.K. performed degradation assays. N.M., W.H.Y., A.L.G. and K.E.D. designed the studies. N.M., A.L.G. and K.E.D. wrote the manuscript. C.L.C., N.V.K. and W.H.Y. contributed to manuscript preparation. W.H.Y. contributed transfected cell lines. All authors reviewed and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Karen E Duff.

Supplementary information

PDF files

  1. 1.

    Supplementary Text and Figures

    Supplementary Figures 1–12 and Supplementary Data

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nm.4011