STK25 suppresses Hippo signaling by regulating SAV1-STRIPAK antagonism
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.
All data generated or analyses during this study are included in the manuscript and supporting files.
Article and author information
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.
- William I. Weis, Stanford University School of Medicine, United States
- Received: January 9, 2020
- Accepted: April 10, 2020
- Accepted Manuscript published: April 15, 2020 (version 1)
- 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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