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Tokamov SA, Buiter S, Ullyot A, Scepanovic G, Williams AM, Fernandez-Gonzalez R, Horne-Badovinac S, Fehon RG. Cortical tension promotes Kibra degradation via Par-1. Mol Biol Cell 2024; 35:ar2. [PMID: 37903240 PMCID: PMC10881160 DOI: 10.1091/mbc.e23-06-0246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/17/2023] [Accepted: 10/20/2023] [Indexed: 11/01/2023] Open
Abstract
The Hippo pathway is an evolutionarily conserved regulator of tissue growth. Multiple Hippo signaling components are regulated via proteolytic degradation. However, how these degradation mechanisms are themselves modulated remains unexplored. Kibra is a key upstream pathway activator that promotes its own ubiquitin-mediated degradation upon assembling a Hippo signaling complex. Here, we demonstrate that Hippo complex-dependent Kibra degradation is modulated by cortical tension. Using classical genetic, osmotic, and pharmacological manipulations of myosin activity and cortical tension, we show that increasing cortical tension leads to Kibra degradation, whereas decreasing cortical tension increases Kibra abundance. Our study also implicates Par-1 in regulating Kib abundance downstream of cortical tension. We demonstrate that Par-1 promotes ubiquitin-mediated Kib degradation in a Hippo complex-dependent manner and is required for tension-induced Kib degradation. Collectively, our results reveal a previously unknown molecular mechanism by which cortical tension affects Hippo signaling and provide novel insights into the role of mechanical forces in growth control.
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Affiliation(s)
- Sherzod A. Tokamov
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
- Committee on Development, Regeneration, and Stem Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Stephan Buiter
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Anne Ullyot
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Gordana Scepanovic
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Audrey Miller Williams
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Rodrigo Fernandez-Gonzalez
- Institute of Biomedical Engineering and Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Sally Horne-Badovinac
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
- Committee on Development, Regeneration, and Stem Cell Biology, The University of Chicago, Chicago, IL 60637
| | - Richard G. Fehon
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637
- Committee on Development, Regeneration, and Stem Cell Biology, The University of Chicago, Chicago, IL 60637
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Gridnev A, Misra JR. Emerging Mechanisms of Growth and Patterning Regulation by Dachsous and Fat Protocadherins. Front Cell Dev Biol 2022; 10:842593. [PMID: 35372364 PMCID: PMC8967653 DOI: 10.3389/fcell.2022.842593] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/08/2022] [Indexed: 01/14/2023] Open
Abstract
Dachsous (Ds) and Fat are evolutionarily conserved cell adhesion molecules that play a critical role in development of multiple organ systems, where they coordinate tissue growth and morphogenesis. Much of our understanding of Ds-Fat signaling pathway comes from studies in Drosophila, where they initiate a signaling pathway that regulate growth by influencing Hippo signaling and morphogenesis by regulating Planar Cell Polarity (PCP). In this review, we discuss recent advances in our understanding of the mechanisms by which Ds-Fat signaling pathway regulates these critical developmental processes. Further, we discuss the progress in our understanding about how they function in mammals.
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Tokamov SA, Su T, Ullyot A, Fehon RG. Negative feedback couples Hippo pathway activation with Kibra degradation independent of Yorkie-mediated transcription. eLife 2021; 10:62326. [PMID: 33555257 PMCID: PMC7895526 DOI: 10.7554/elife.62326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/08/2021] [Indexed: 12/20/2022] Open
Abstract
The Hippo (Hpo) pathway regulates tissue growth in many animals. Multiple upstream components promote Hpo pathway activity, but the organization of these different inputs, the degree of crosstalk between them, and whether they are regulated in a distinct manner is not well understood. Kibra (Kib) activates the Hpo pathway by recruiting the core Hpo kinase cassette to the apical cortex. Here, we show that the Hpo pathway downregulates Drosophila Kib levels independently of Yorkie-mediated transcription. We find that Hpo signaling complex formation promotes Kib degradation via SCFSlimb-mediated ubiquitination, that this effect requires Merlin, Salvador, Hpo, and Warts, and that this mechanism functions independently of other upstream Hpo pathway activators. Moreover, Kib degradation appears patterned by differences in mechanical tension across the wing. We propose that Kib degradation mediated by Hpo pathway components and regulated by cytoskeletal tension serves to control Kib-driven Hpo pathway activation and ensure optimally scaled and patterned tissue growth.
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Affiliation(s)
- Sherzod A Tokamov
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, United States.,Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, United States
| | - Ting Su
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, United States
| | - Anne Ullyot
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, United States
| | - Richard G Fehon
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, United States.,Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, United States
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Nagai H, Tatara H, Tanaka-Furuhashi K, Kurata S, Yano T. Homeostatic Regulation of ROS-Triggered Hippo-Yki Pathway via Autophagic Clearance of Ref(2)P/p62 in the Drosophila Intestine. Dev Cell 2021; 56:81-94.e10. [PMID: 33400912 DOI: 10.1016/j.devcel.2020.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/23/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022]
Abstract
Homeostasis of intestinal epithelia is maintained by coordination of the proper rate of regeneration by stem cell division with the rate of cell loss. Regeneration of host epithelia is normally quiescent upon colonization of commensal bacteria; however, the epithelia often develop dysplasia in a context-dependent manner, the cause and underlying mechanism of which remain unclear. Here, we show that in Drosophila intestine, autophagy lowers the sensitivity of differentiated enterocytes to reactive oxygen species (ROS) that are produced in response to commensal bacteria. We find that autophagy deficiency provokes ROS-dependent excessive regeneration and subsequent epithelial dysplasia and barrier dysfunction. Mechanistically, autophagic substrate Ref(2)P/p62, which co-localizes and physically interacts with Dachs, a Hippo signaling regulator, accumulates upon autophagy deficiency and thus inactivates Hippo signaling, resulting in stem cell over-proliferation non-cell autonomously. Our findings uncover a mechanism whereby suppression of undesirable regeneration by autophagy maintains long-term homeostasis of intestinal epithelia.
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Affiliation(s)
- Hiroki Nagai
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Hiroshi Tatara
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | | | - Shoichiro Kurata
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.
| | - Tamaki Yano
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.
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Fat/Dachsous family cadherins in cell and tissue organisation. Curr Opin Cell Biol 2020; 62:96-103. [DOI: 10.1016/j.ceb.2019.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/24/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023]
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