Protein accumulation and neurodegeneration in the woozy mutant mouse is caused by disruption of SIL1, a cochaperone of BiP

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Abstract

Endoplasmic reticulum (ER) chaperones and ER stress have been implicated in the pathogenesis of neurodegenerative disorders, such as Alzheimer and Parkinson diseases, but their contribution to neuron death remains uncertain1,2. In this study, we establish a direct in vivo link between ER dysfunction and neurodegeneration. Mice homozygous with respect to the woozy (wz) mutation develop adult-onset ataxia with cerebellar Purkinje cell loss. Affected cells have intracellular protein accumulations reminiscent of protein inclusions in both the ER and the nucleus. In addition, upregulation of the unfolded protein response, suggestive of ER stress, occurs in mutant Purkinje cells. We report that the wz mutation disrupts the gene Sil1 that encodes an adenine nucleotide exchange factor of BiP3, a crucial ER chaperone4. These findings provide evidence that perturbation of ER chaperone function in terminally differentiated neurons leads to protein accumulation, ER stress and subsequent neurodegeneration.

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Figure 1: Purkinje neuron degeneration in the woozy mutant cerebellum.
Figure 2: Identification of Sil1 as the wz locus.
Figure 3: The wz mutation results in formation of protein accumulations in Purkinje cells.
Figure 4: Localization of protein accumulations in Purkinje cells.
Figure 5: Truncation of Sil1 induces the ER stress response.
Figure 6: ER stress response in wz Purkinje cells.

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References

  1. 1

    Nakagawa, T. et al. Caspase-12 mediates endoplasmic-reticulum-specific apoptosis and cytotoxicity by amyloid-beta. Nature 403, 98–103 (2000).

  2. 2

    Imai, Y. et al. An unfolded putative transmembrane polypeptide, which can lead to endoplasmic reticulum stress, is a substrate of Parkin. Cell 105, 891–902 (2001).

  3. 3

    Chung, K.T., Shen, Y. & Hendershot, L.M. BAP, a mammalian BiP-associated protein, is a nucleotide exchange factor that regulates the ATPase activity of BiP. J. Biol. Chem. 277, 47557–47563 (2002).

  4. 4

    Rose, M.D., Misra, L.M. & Vogel, J.P. KAR2, a karyogamy gene, is the yeast homolog of the mammalian BiP/GRP78 gene. Cell 57, 1211–1221 (1989).

  5. 5

    Selkoe, D.J. Folding proteins in fatal ways. Nature 426, 900–904 (2003).

  6. 6

    Cummings, C.J. et al. Chaperone suppression of aggregation and altered subcellular proteasome localization imply protein misfolding in SCA1. Nat. Genet. 19, 148–154 (1998).

  7. 7

    Warrick, J.M. et al. Suppression of polyglutamine-mediated neurodegeneration in Drosophila by the molecular chaperone HSP70. Nat. Genet. 23, 425–428 (1999).

  8. 8

    Southwood, C.M., Garbern, J., Jiang, W. & Gow, A. The unfolded protein response modulates disease severity in Pelizaeus-Merzbacher disease. Neuron 36, 585–596 (2002).

  9. 9

    Larsen, K.E. & Sulzer, D. Autophagy in neurons: a review. Histol. Histopathol. 17, 897–908 (2002).

  10. 10

    Skarnes, W.C., Moss, J.E., Hurtley, S.M. & Beddington, R.S. Capturing genes encoding membrane and secreted proteins important for mouse development. Proc. Natl. Acad. Sci. USA 92, 6592–6596 (1995).

  11. 11

    Tyson, J.R. & Stirling, C.J. LHS1 and SIL1 provide a lumenal function that is essential for protein translocation into the endoplasmic reticulum. EMBO J. 19, 6440–6452 (2000).

  12. 12

    Gething, M.J. Role and regulation of the ER chaperone BiP. Semin. Cell Dev. Biol. 10, 465–472 (1999).

  13. 13

    Kabani, M., Beckerich, J.M. & Gaillardin, C. Sls1p stimulates Sec63p-mediated activation of Kar2p in a conformation-dependent manner in the yeast endoplasmic reticulum. Mol. Cell. Biol. 20, 6923–6934 (2000).

  14. 14

    Ross, C.A. & Pickart, C.M. The ubiquitin-proteasome pathway in Parkinson's disease and other neurodegenerative diseases. Trends Cell Biol. 14, 703–711 (2004).

  15. 15

    Ron, D. Translational control in the endoplasmic reticulum stress response. J. Clin. Invest. 110, 1383–1388 (2002).

  16. 16

    Ma, Y. & Hendershot, L.M. The unfolding tale of the unfolded protein response. Cell 107, 827–830 (2001).

  17. 17

    Zhang, K. & Kaufman, R.J. Signaling the unfolded protein response from the endoplasmic reticulum. J. Biol. Chem. 279, 25935–25938 (2004).

  18. 18

    Kimata, Y. et al. Genetic evidence for a role of BiP/Kar2 that regulates Ire1 in response to accumulation of unfolded proteins. Mol. Biol. Cell 14, 2559–2569 (2003).

  19. 19

    Lee, A.S. The glucose-regulated proteins: stress induction and clinical applications. Trends Biochem. Sci. 26, 504–510 (2001).

  20. 20

    Wang, X.Z. et al. Signals from the stressed endoplasmic reticulum induce C/EBP-homologous protein (CHOP/GADD153). Mol. Cell. Biol. 16, 4273–4280 (1996).

  21. 21

    Zinszner, H. et al. CHOP is implicated in programmed cell death in response to impaired function of the endoplasmic reticulum. Genes Dev. 12, 982–995 (1998).

  22. 22

    Lin, X., Antalffy, B., Kang, D., Orr, H.T. & Zoghbi, H.Y. Polyglutamine expansion down-regulates specific neuronal genes before pathologic changes in SCA1. Nat. Neurosci. 3, 157–163 (2000).

  23. 23

    Altman, J. & Bayer, S.A. Development of the Cerebellar System: In Relation to its Evolution, Structure and Functions (CRC Press, Inc., Boca Raton, Florida, 1997).

  24. 24

    Tessitore, A. et al. GM1-ganglioside-mediated activation of the unfolded protein response causes neuronal death in a neurodegenerative gangliosidosis. Mol. Cell 15, 753–766 (2004).

  25. 25

    Slemmer, J.E., De Zeeuw, C.I. & Weber, J.T. Don't get too excited: mechanisms of glutamate-mediated Purkinje cell death. Prog. Brain Res. 148, 367–390 (2005).

  26. 26

    Fletcher, C.F. et al. Absence epilepsy in tottering mutant mice is associated with calcium channel defects. Cell 87, 607–617 (1996).

  27. 27

    Kitao, Y. et al. ORP150/HSP12A regulates Purkinje cell survival: a role for endoplasmic reticulum stress in cerebellar development. J. Neurosci. 24, 1486–1496 (2004).

  28. 28

    Serra, H.G. et al. Gene profiling links SCA1 pathophysiology to glutamate signaling in Purkinje cells of transgenic mice. Hum. Mol. Genet. 13, 2535–2543 (2004).

  29. 29

    Ackerman, S.L. et al. The mouse rostral cerebellar malformation gene encodes an UNC-5-like protein. Nature 386, 838–842 (1997).

  30. 30

    Goldowitz, D., Hamre, K.M., Przyborski, S.A. & Ackerman, S.L. Granule cells and cerebellar boundaries: analysis of Unc5h3 mutant chimeras. J. Neurosci. 20, 4129–4137 (2000).

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Acknowledgements

We thank The Jackson Laboratory sequencing facility, histology, microinjection and bioimaging services for their contributions; R. Bronson for assistance with electron microscopy; and L.L. Beverly-Staggs for technical assistance. We also thank BayGenomics, which is supported by the US National Heart, Lung, and Blood Institute. This study is supported by grants from the US National Institutes of Health (S.L.A) and a Mouse Mutant Resource grant from the US National Institutes of Health.

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Correspondence to Susan L Ackerman.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Fig. 1

Co-localization of SIL1 and BiP. (PDF 850 kb)

Supplementary Fig. 2

SIL1 truncated by the wz mutation retains the ability to interact with BiP. (PDF 163 kb)

Supplementary Table 1

Primers used in Sil1 genomic and RT-PCR. (PDF 27 kb)

Supplementary Video 1

A four-month old CxB5/ByJ-woozy mutant mouse (wz/wz) and its wild type littermate (+/+) are shown. Note the tremors and truncal ataxia in the wz/wz mouse. (MOV 1368 kb)

Supplementary Methods (PDF 34 kb)

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Zhao, L., Longo-Guess, C., Harris, B. et al. Protein accumulation and neurodegeneration in the woozy mutant mouse is caused by disruption of SIL1, a cochaperone of BiP. Nat Genet 37, 974–979 (2005) doi:10.1038/ng1620

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