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The clathrin adaptor Numb regulates intestinal cholesterol absorption through dynamic interaction with NPC1L1

Nature Medicine volume 20, pages 8086 (2014) | Download Citation

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Abstract

Hypercholesterolemia, typically due to excessive cholesterol uptake, is a major risk factor for cardiovascular disease, which is responsible for 50% of all deaths in developed societies. Although it has been shown that intestinal cholesterol absorption is mediated by vesicular endocytosis of the Niemann-Pick C1–like 1 (NPC1L1) protein1,2, the mechanism of sterol-stimulated NPC1L1 internalization is still mysterious. Here, we identified an endocytic peptide signal, YVNXXF (where X stands for any amino acid), in the cytoplasmic C-terminal tail of NPC1L1. Cholesterol binding on the N-terminal domain of NPC1L1 released the YVNXXF-containing region of NPC1L1 from association with the plasma membrane and enabled Numb binding. We also found that Numb, a clathrin adaptor, specifically recognized this motif and recruited clathrin for internalization. Disrupting the NPC1L1-Numb interaction decreased cholesterol uptake. Ablation of Numb in mouse intestine significantly reduced dietary cholesterol absorption and plasma cholesterol level. Together, these data show that Numb is a pivotal protein for intestinal cholesterol absorption and may provide a therapeutic target for hypercholesterolemia.

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Acknowledgements

We thank Y.-X. Qu, J. Xu and J. Qin for technical assistance. We thank W. Qi for helpful discussion and revision of the paper. We thank S. Robine (Institut Curie) for the gift of transgenic mice (heterozygous for villin-Cre-ERT2). We thank S. Kathiresan, X. Lin and X.-F. Lu for discussions. This work was supported by grants from the Ministry of Science and Technology of China (2009CB919000, 2011CB910900 and 2012CB524900), National Natural Science Foundation of China (30925012, 31230020, 81260041, 81270155 and 91213306), Shanghai Science and Technology Committee (11JC1414100) and Xinjiang Science and Technology Department (2013911111).

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Affiliations

  1. The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.

    • Pei-Shan Li
    • , Zhen-Yan Fu
    • , Ying-Yu Zhang
    • , Jin-Hui Zhang
    • , Chen-Qi Xu
    • , Bo-Liang Li
    •  & Bao-Liang Song
  2. Department of Cardiovascular Medicine, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China.

    • Zhen-Yan Fu
    •  & Yi-Tong Ma

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Contributions

P.-S.L., C.-Q.X., Y.-T.M., B.-L.L. and B.-L.S. conceived the project. P.-S.L. and B.-L.S. designed the experiments. P.-S.L., Z.-Y.F., Y.-Y.Z. and J.-H.Z. performed the experiments. P.-S.L., C.-Q.X., B.-L.L. and B.-L.S. analyzed the data. P.-S.L. and B.-L.S. wrote the paper.

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The authors declare no competing financial interests.

Corresponding author

Correspondence to Bao-Liang Song.

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https://doi.org/10.1038/nm.3417

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