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Lysosomal cholesterol accumulation contributes to the movement phenotypes associated with NUS1 haploinsufficiency



Variants in NUS1 are associated with a congenital disorder of glycosylation, developmental and epileptic encephalopathies, and are possible contributors to Parkinson disease pathogenesis. How the diverse functions of the NUS1-encoded Nogo B receptor (NgBR) relate to these different phenotypes is largely unknown. We present three patients with de novo heterozygous variants in NUS1 that cause a complex movement disorder, define pathogenic mechanisms in cells and zebrafish, and identify possible therapy.


Comprehensive functional studies were performed using patient fibroblasts, and a zebrafish model mimicking NUS1 haploinsufficiency.


We show that de novo NUS1 variants reduce NgBR and Niemann–Pick type C2 (NPC2) protein amount, impair dolichol biosynthesis, and cause lysosomal cholesterol accumulation. Reducing nus1 expression 50% in zebrafish embryos causes abnormal swim behaviors, cholesterol accumulation in the nervous system, and impaired turnover of lysosomal membrane proteins. Reduction of cholesterol buildup with 2-hydroxypropyl-ß-cyclodextrin significantly alleviates lysosomal proteolysis and motility defects.


Our results demonstrate that these NUS1 variants cause multiple lysosomal phenotypes in cells. We show that the movement deficits associated with nus1 reduction in zebrafish arise in part from defective efflux of cholesterol from lysosomes, suggesting that treatments targeting cholesterol accumulation could be therapeutic.

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Fig. 1: De novo NUS1 variants cause a spectrum of lysosomal defects in patient cells.
Fig. 2: Reduction in nus1 expression alters swim behavior of zebrafish embryos.
Fig. 3: nus1 morphants exhibit impaired lysosomal function and cholesterol accumulation.
Fig. 4: Treatment with ßCD reduces cholesterol accumulation and restores lysosomal function.
Fig. 5: Lowering cholesterol accumulation improves swim behaviors in nus1 morphant embryos.

Web Resources

Provean (protein variation effect analyser), PolyPhen2, MutationTaster, dbSNP, gnomAD, Mutalyzer, ClinVar,

Data and code availability

All variants described in this study have been deposited in ClinVar; accession numbers are VCV000981036, VCV000981034, VCV000981035 (Submission ID: SUB8124960; Organization ID: 1019).


  1. 1.

    Bar-El, M. L. et al. Structural basis of heterotetrameric assembly and disease mutations in the human cis-prenyltransferase complex. Nat. Commun. 11, 5273 (2020).

    CAS  Article  Google Scholar 

  2. 2.

    Edani, B. H. et al. Structural elucidation of the cis-prenyltransferase NgBR/DHDDS complex reveals insights in regulation of protein glycosylation. Proc. Natl. Acad. Sci. U. S. A. 117, 20794–20802 (2020).

    CAS  Article  Google Scholar 

  3. 3.

    Grabinska, K. A., Edani, B. H., Park, E. J., Kraehling, J. R. & Sessa, W. C. A conserved C-terminal RXG motif in the NgBR subunit of cis-prenyltransferase is critical for prenyltransferase activity. J. Biol. Chem. 292, 17351–17361 (2017).

    CAS  Article  Google Scholar 

  4. 4.

    Grabinska, K. A., Park, E. J. & Sessa, W. C. cis-Prenyltransferase: new insights into protein glycosylation, rubber synthesis, and human diseases. J. Biol. Chem. 291, 18582–18590 (2016).

    CAS  Article  Google Scholar 

  5. 5.

    Harrison, K. D. et al. Nogo-B receptor is necessary for cellular dolichol biosynthesis and protein N-glycosylation. EMBO J. 30, 2490–2500 (2011).

    CAS  Article  Google Scholar 

  6. 6.

    Harrison, K. D. et al. Nogo-B receptor stabilizes Niemann–Pick type C2 protein and regulates intracellular cholesterol trafficking. Cell Metab. 10, 208–218 (2009).

    CAS  Article  Google Scholar 

  7. 7.

    Park, E. J., Grabinska, K. A., Guan, Z. & Sessa, W. C. NgBR is essential for endothelial cell glycosylation and vascular development. EMBO Rep. 17, 167–177 (2016).

    CAS  Article  Google Scholar 

  8. 8.

    Miao, R. Q. et al. Identification of a receptor necessary for Nogo-B stimulated chemotaxis and morphogenesis of endothelial cells. Proc. Natl. Acad. Sci. U. S. A. 103, 10997–11002 (2006).

    CAS  Article  Google Scholar 

  9. 9.

    Teng, R. J. et al. Nogo-B receptor modulates angiogenesis response of pulmonary artery endothelial cells through eNOS coupling. Am. J. Respir. Cell Mol. Biol. 51, 169–177 (2014).

    PubMed  PubMed Central  Google Scholar 

  10. 10.

    Park, E. J. et al. Mutation of Nogo-B receptor, a subunit of cis-prenyltransferase, causes a congenital disorder of glycosylation. Cell Metab. 20, 448–457 (2014).

    CAS  Article  Google Scholar 

  11. 11.

    Hamdan, F. F. et al. High rate of recurrent de novo mutations in developmental and epileptic encephalopathies. Am. J. Hum. Genet. 101, 664–685 (2017).

    CAS  Article  Google Scholar 

  12. 12.

    Chen, X. et al. Genetic analysis of NUS1 in Chinese patients with Parkinson’s disease. Neurobiol. Aging. 86, 202 e205–202 e206 (2020).

    Article  Google Scholar 

  13. 13.

    Guo, J. F. et al. Coding mutations in NUS1 contribute to Parkinson’s disease. Proc. Natl. Acad. Sci. U. S. A. 115, 11567–11572 (2018).

    CAS  Article  Google Scholar 

  14. 14.

    Bustos, B. I. et al. Replication assessment of NUS1 variants in Parkinson’s disease. Neurobiol. Aging. S0197-4580, 30389–4 (2020).

    Google Scholar 

  15. 15.

    Yuan, L. et al. Extended study of NUS1 gene variants in Parkinson’s disease. Front. Neurol. 11, 583182 (2020).

    Article  Google Scholar 

  16. 16.

    Araki, K. et al. NUS1 mutation in a family with epilepsy, cerebellar ataxia, and tremor. Epilepsy Res. 164, 106371 (2020).

    CAS  Article  Google Scholar 

  17. 17.

    Den, K. et al. Recurrent NUS1 canonical splice donor site mutation in two unrelated individuals with epilepsy, myoclonus, ataxia and scoliosis—a case report. BMC Neurol. 19, 253 (2019).

    Article  Google Scholar 

  18. 18.

    Szafranski, P. et al. 6q22.1 microdeletion and susceptibility to pediatric epilepsy. Eur. J. Hum. Genet. 23, 173–179 (2015).

    CAS  Article  Google Scholar 

  19. 19.

    Wirth, T. et al. Increased diagnostic yield in complex dystonia through exome sequencing. Parkinsonism Related Disord. 74, 50–56 (2020).

    Article  Google Scholar 

  20. 20.

    Reczek, D. et al. LIMP-2 is a receptor for lysosomal mannose-6-phosphate-independent targeting of beta-glucocerebrosidase. Cell. 131, 770–783 (2007).

    CAS  Article  Google Scholar 

  21. 21.

    Zhao, Y., Ren, J., Padilla-Parra, S., Fry, E. E. & Stuart, D. I. Lysosome sorting of beta-glucocerebrosidase by LIMP-2 is targeted by the mannose 6-phosphate receptor. Nat. Commun. 5, 4321 (2014).

    CAS  Article  Google Scholar 

  22. 22.

    Zunke, F. et al. Characterization of the complex formed by beta-glucocerebrosidase and the lysosomal integral membrane protein type-2. Proc. Natl. Acad. Sci. U. S. A. 113, 3791–3796 (2016).

    CAS  Article  Google Scholar 

  23. 23.

    Lek, M. et al. Analysis of protein-coding genetic variation in 60,706 humans. Nature. 536, 285–291 (2016).

    CAS  Article  Google Scholar 

  24. 24.

    Ory, D. S. et al. Intrathecal 2-hydroxypropyl-beta-cyclodextrin decreases neurological disease progression in Niemann–Pick disease, type C1: a non-randomised, open-label, phase 1-2 trial. Lancet. 390, 1758–1768 (2017).

    CAS  Article  Google Scholar 

  25. 25.

    Elrick, M. J. & Lieberman, A. P. Autophagic dysfunction in a lysosomal storage disorder due to impaired proteolysis. Autophagy. 9, 234–235 (2013).

    CAS  Article  Google Scholar 

  26. 26.

    Elrick, M. J., Yu, T., Chung, C. & Lieberman, A. P. Impaired proteolysis underlies autophagic dysfunction in Niemann–Pick type C disease. Hum. Mol. Genet. 21, 4876–4887 (2012).

    CAS  Article  Google Scholar 

  27. 27.

    Nguyen, M., Wong, Y. C., Ysselstein, D., Severino, A. & Krainc, D. Synaptic, mitochondrial, and lysosomal dysfunction in Parkinson’s disease. Trends Neurosci. 42, 140–149 (2019).

    CAS  Article  Google Scholar 

  28. 28.

    Wong, Y. C. et al. Neuronal vulnerability in Parkinson disease: should the focus be on axons and synaptic terminals? Mov. Disord. 34, 1406–1422 (2019).

    CAS  Article  Google Scholar 

  29. 29.

    Lloyd-Evans, E. et al. Niemann–Pick disease type C1 is a sphingosine storage disease that causes deregulation of lysosomal calcium. Nat. Med. 14, 1247–1255 (2008).

    CAS  Article  Google Scholar 

  30. 30.

    Haeuptle, M. A. et al. Improvement of dolichol-linked oligosaccharide biosynthesis by the squalene synthase inhibitor zaragozic acid. J. Biol. Chem. 286, 6085–6091 (2011).

    CAS  Article  Google Scholar 

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We acknowledge the patients and their families for their willingness to participate in this study. This work was supported by the Greenwood Genetic Center and grants from the National Institutes of Health (5R01-GM086524-11 to R.S. and H.F-S; AI108819 to M.B.C). We acknowledge the support of the Hazel and Bill Allin Aquaculture Facility housed at the Greenwood Genetic Center and thank the facility staff for their excellent animal care.

Author information




Conceptualization: R.S., H.F.-S., M.J.L. Data curation: S.Y., T.W., E.F.M., M.B.C., R.J.L., H.F.-S., R.S. Formal analysis: S.Y., T.W., R.J.L., H.F.-S., R.S. Funding acquisition: R.S., H.F.-S., M.B.C. Investigation: S.Y., T.W., K.W., R.J.L., E.F.M., H.F.-S. Methodology: S.Y., T.W., M.B.C., H.F.-S., R.S. Project administration: R.S., H.F.-S., M.J.L. Resources: C.S., K.M., P.G., N.R., D.C., M.J.L. Supervision: R.S., H.F.-S. Validation: T.W., H.F.-S. Visualization: S.Y., T.W., H.F.-S. Writing—original draft: R.S., H.F.-S., M.J.L., R.J.L. Writing—review & editing: R.S., H.F.-S.

Corresponding author

Correspondence to Richard Steet.

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Ethics declaration

Informed consents were signed by the parents of the proband and other patients prior to participation in the research. All procedures were employed after being reviewed and approved by the Institutional Review Board, and compliant with practices, at the Greenwood Genetic Center (GGC). Handling and euthanasia of fish complied with policies of the GGC, as approved by the GGC’s Institutional Animal Care and Use Committee (permit #A2019-01-003-A1).

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The authors declare no competing interests.

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Yu, SH., Wang, T., Wiggins, K. et al. Lysosomal cholesterol accumulation contributes to the movement phenotypes associated with NUS1 haploinsufficiency. Genet Med 23, 1305–1314 (2021).

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