Double NPY motifs at the N-terminus of the yeast t-SNARE Sso2 synergistically bind Sec3 to promote membrane fusion

  1. Maximilian Peer
  2. Hua Yuan
  3. Yubo Zhang
  4. Katharina Korbula
  5. Peter Novick  Is a corresponding author
  6. Gang Dong  Is a corresponding author
  1. Medical University of Vienna, Austria
  2. University of California, San Diego, United States
  3. Medical Unviersity of Vienna, Austria

Abstract

Exocytosis is an active vesicle trafficking process by which eukaryotes secrete materials to the extracellular environment and insert membrane proteins into the plasma membrane. The final step of exocytosis in yeast involves the assembly of two t-SNAREs, Sso1/2 and Sec9, with the v-SNARE, Snc1/2, on secretory vesicles. The rate-limiting step in this process is the formation of a binary complex of the two t-SNAREs. Despite a previous report of acceleration of binary complex assembly by Sec3, it remains unknown how Sso2 is efficiently recruited to the vesicle-docking site marked by Sec3. Here we report a crystal structure of the pleckstrin homology (PH) domain of Sec3 in complex with a nearly full-length version of Sso2 lacking only its C-terminal transmembrane helix. The structure shows a previously uncharacterized binding site for Sec3 at the N-terminus of Sso2, consisting of two highly conserved triple residue motifs (NPY: Asn-Pro-Tyr). We further reveal that the two NPY motifs bind Sec3 synergistically, which together with the previously reported binding interface constitute dual-site interactions between Sso2 and Sec3 to drive the fusion of secretory vesicles at target sites on the plasma membrane.

Data availability

Diffraction data have been deposited in PDB under the accession code 7Q83.

Article and author information

Author details

  1. Maximilian Peer

    Vienna Biocenter, Medical University of Vienna, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5032-8029
  2. Hua Yuan

    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Yubo Zhang

    Vienna Biocenter, Medical University of Vienna, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  4. Katharina Korbula

    Vienna Biocenter, Medical University of Vienna, Vienna, Austria
    Competing interests
    The authors declare that no competing interests exist.
  5. Peter Novick

    Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, United States
    For correspondence
    pnovick@ucsd.edu
    Competing interests
    The authors declare that no competing interests exist.
  6. Gang Dong

    Medical Unviersity of Vienna, Vienna, Austria
    For correspondence
    gang.dong@meduniwien.ac.at
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9745-8103

Funding

Austrian Science Fund (P28231-B28)

  • Gang Dong

Austrian Science Fund (I4960-B)

  • Gang Dong

National Institutes of Health (GM35370)

  • Peter Novick

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Volker Dötsch, Goethe University, Germany

Publication history

  1. Preprint posted: March 12, 2022 (view preprint)
  2. Received: July 20, 2022
  3. Accepted: July 29, 2022
  4. Accepted Manuscript published: August 18, 2022 (version 1)
  5. Version of Record published: August 30, 2022 (version 2)

Copyright

© 2022, Peer 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.

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  1. Maximilian Peer
  2. Hua Yuan
  3. Yubo Zhang
  4. Katharina Korbula
  5. Peter Novick
  6. Gang Dong
(2022)
Double NPY motifs at the N-terminus of the yeast t-SNARE Sso2 synergistically bind Sec3 to promote membrane fusion
eLife 11:e82041.
https://doi.org/10.7554/eLife.82041

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