1. Structural Biology and Molecular Biophysics

Molecular assembly of the period-cryptochrome circadian transcriptional repressor complex

  1. Shannon N Nangle
  2. Clark Rosensweig
  3. Nobuya Koike
  4. Hajime Tei
  5. Joseph S Takahashi
  6. Carla B Green
  7. Ning Zheng  Is a corresponding author
  1. University of Washington, United States
  2. University of Texas, Southwestern Medical Center, United States
  3. Kyoto Prefectural University of Medicine, Japan
  4. Graduate School of Natural Science and Technology, Kanazawa University, Japan
  5. University of Texas Southwestern Medical Center, United States
  6. The University of Texas Southwestern Medical Center, United States
https://doi.org/10.7554/eLife.03674
Share this article
Cite this article
  1. Shannon N Nangle
  2. Clark Rosensweig
  3. Nobuya Koike
  4. Hajime Tei
  5. Joseph S Takahashi
  6. Carla B Green
  7. Ning Zheng
(2014)
Molecular assembly of the period-cryptochrome circadian transcriptional repressor complex
eLife 3:e03674.
https://doi.org/10.7554/eLife.03674
  2. Download BibTeX
  3. Download .RIS

Abstract

The mammalian circadian clock is driven by a transcriptional-translational feedback loop, which produces robust 24-hr rhythms. Proper oscillation of the clock depends on the complex formation and periodic turnover of the Period and Cryptochrome proteins, which together inhibit their own transcriptional activator complex, CLOCK-BMAL1. We determined the crystal structure of the CRY-binding domain (CBD) of PER2 in complex with CRY2 at 2.8 Å resolution. PER2-CBD adopts a highly extended conformation, embracing CRY2 with a sinuous binding mode. Its N-terminal end tucks into CRY adjacent to a large pocket critical for CLOCK-BMAL1 binding, while its C-terminal half flanks the CRY2 C-terminal helix and sterically hinders the recognition of CRY2 by the FBXL3 ubiquitin ligase. Unexpectedly, a strictly conserved intermolecular zinc finger, whose integrity is important for clock rhythmicity, further stabilizes the complex. Our structure-guided analyses show that these interspersed CRY-interacting regions represent multiple functional modules of PERs at the CRY-binding interface.

Article and author information

Author details

  1. Shannon N Nangle

    University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Clark Rosensweig

    University of Texas, Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Nobuya Koike

    Kyoto Prefectural University of Medicine, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.

  4. Hajime Tei

    Graduate School of Natural Science and Technology, Kanazawa University, Ishikawa, Japan
    Competing interests
    The authors declare that no competing interests exist.

  5. Joseph S Takahashi

    University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Carla B Green

    The University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Ning Zheng

    University of Washington, Seattle, United States
    For correspondence
    nzheng@uw.edu
    Competing interests
    The authors declare that no competing interests exist.

Copyright

© 2014, Nangle et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 4,267
    views
  • 554
    downloads
  • 95
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Shannon N Nangle
  2. Clark Rosensweig
  3. Nobuya Koike
  4. Hajime Tei
  5. Joseph S Takahashi
  6. Carla B Green
  7. Ning Zheng
(2014)
Molecular assembly of the period-cryptochrome circadian transcriptional repressor complex
eLife 3:e03674.
https://doi.org/10.7554/eLife.03674

Share this article

https://doi.org/10.7554/eLife.03674

Categories and tags

Research organism

Further reading

    1. Developmental Biology
    2. Structural Biology and Molecular Biophysics

    The co-receptor Tetraspanin12 directly captures Norrin to promote ligand-specific β-catenin signaling

    Elise S Bruguera, Jacob P Mahoney, William I Weis
    Research Article

    Wnt/β-catenin signaling directs animal development and tissue renewal in a tightly controlled, cell- and tissue-specific manner. In the mammalian central nervous system, the atypical ligand Norrin controls angiogenesis and maintenance of the blood-brain barrier and blood-retina barrier through the Wnt/β-catenin pathway. Like Wnt, Norrin activates signaling by binding and heterodimerizing the receptors Frizzled (Fzd) and low-density lipoprotein receptor-related protein 5 or 6 (LRP5/6), leading to membrane recruitment of the intracellular transducer Dishevelled (Dvl) and ultimately stabilizing the transcriptional coactivator β-catenin. Unlike Wnt, the cystine knot ligand Norrin only signals through Fzd4 and additionally requires the co-receptor Tetraspanin12 (Tspan12); however, the mechanism underlying Tspan12-mediated signal enhancement is unclear. It has been proposed that Tspan12 integrates into the Norrin-Fzd4 complex to enhance Norrin-Fzd4 affinity or otherwise allosterically modulate Fzd4 signaling. Here, we measure direct, high-affinity binding between purified Norrin and Tspan12 in a lipid environment and use AlphaFold models to interrogate this interaction interface. We find that Tspan12 and Fzd4 can simultaneously bind Norrin and that a pre-formed Tspan12/Fzd4 heterodimer, as well as cells co-expressing Tspan12 and Fzd4, more efficiently capture low concentrations of Norrin than Fzd4 alone. We also show that Tspan12 competes with both heparan sulfate proteoglycans and LRP6 for Norrin binding and that Tspan12 does not impact Fzd4-Dvl affinity in the presence or absence of Norrin. Our findings suggest that Tspan12 does not allosterically enhance Fzd4 binding to Norrin or Dvl, but instead functions to directly capture Norrin upstream of signaling.

    1. Structural Biology and Molecular Biophysics

    The known unknowns of the Hsp90 chaperone

    Laura-Marie Silbermann, Benjamin Vermeer ... Katarzyna Tych
    Review Article

    Molecular chaperones are vital proteins that maintain protein homeostasis by assisting in protein folding, activation, degradation, and stress protection. Among them, heat-shock protein 90 (Hsp90) stands out as an essential proteostasis hub in eukaryotes, chaperoning hundreds of ‘clients’ (substrates). After decades of research, several ‘known unknowns’ about the molecular function of Hsp90 remain unanswered, hampering rational drug design for the treatment of cancers, neurodegenerative, and other diseases. We highlight three fundamental open questions, reviewing the current state of the field for each, and discuss new opportunities, including single-molecule technologies, to answer the known unknowns of the Hsp90 chaperone.

    1. Structural Biology and Molecular Biophysics

    N-acetylation of α-synuclein enhances synaptic vesicle clustering mediated by α-synuclein and lysophosphatidylcholine

    Chuchu Wang, Chunyu Zhao ... Cong Liu
    Research Advance

    Previously, we reported that α-synuclein (α-syn) clusters synaptic vesicles (SV) Diao et al., 2013, and neutral phospholipid lysophosphatidylcholine (LPC) can mediate this clustering Lai et al., 2023. Meanwhile, post-translational modifications (PTMs) of α-syn such as acetylation and phosphorylation play important yet distinct roles in regulating α-syn conformation, membrane binding, and amyloid aggregation. However, how PTMs regulate α-syn function in presynaptic terminals remains unclear. Here, based on our previous findings, we further demonstrate that N-terminal acetylation, which occurs under physiological conditions and is irreversible in mammalian cells, significantly enhances the functional activity of α-syn in clustering SVs. Mechanistic studies reveal that this enhancement is caused by the N-acetylation-promoted insertion of α-syn’s N-terminus and increased intermolecular interactions on the LPC-containing membrane. N-acetylation in our work is shown to fine-tune the interaction between α-syn and LPC, mediating α-syn’s role in synaptic vesicle clustering.