1. Cell Biology
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STK25 suppresses Hippo signaling by regulating SAV1-STRIPAK antagonism

  1. Sung Jun Bae
  2. Lisheng Ni
  3. Xuelian Luo  Is a corresponding author
  1. University of Texas Southwestern Medical Center, United States
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Cite this article as: eLife 2020;9:e54863 doi: 10.7554/eLife.54863


The MST-LATS kinase cascade is central to the Hippo pathway that controls tissue homeostasis, development, and organ size. The PP2A complex STRIPAKSLMAP blocks MST1/2 activation. The GCKIII family kinases associate with STRIPAK, but the functions of these phosphatase-associated kinases remain elusive. We previously showed that the scaffolding protein SAV1 promotes Hippo signaling by counteracting STRIPAK (Bae et al. 2017). Here, we show that the GCKIII kinase STK25 promotes STRIPAK-mediated inhibition of MST2 in human cells. Depletion of STK25 enhances MST2 activation without affecting the integrity of STRIPAKSLMAP. STK25 directly phosphorylates SAV1 and diminishes the ability of SAV1 to inhibit STRIPAK. Thus, STK25 as the kinase component of STRIPAK can inhibit the function of the STRIPAK inhibitor SAV1. This mutual antagonism between STRIPAK and SAV1 controls the initiation of Hippo signaling.

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All data generated or analyses during this study are included in the manuscript and supporting files.

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Author details

  1. Sung Jun Bae

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

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

    Departments of Pharmacology and Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5058-4695


National Institute of General Medical Sciences (GM107415)

  • Xuelian Luo

National Institute of General Medical Sciences (GM132275)

  • Xuelian Luo

Welch Foundation (I-1932)

  • Xuelian Luo

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

Reviewing Editor

  1. William I. Weis, Stanford University School of Medicine, United States

Publication history

  1. Received: January 9, 2020
  2. Accepted: April 10, 2020
  3. Accepted Manuscript published: April 15, 2020 (version 1)
  4. Version of Record published: April 24, 2020 (version 2)


© 2020, Bae 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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