51
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Kouwaki T, Okamoto M, Tsukamoto H, Fukushima Y, Matsumoto M, Seya T, Oshiumi H. Zyxin stabilizes RIG-I and MAVS interactions and promotes type I interferon response. Sci Rep 2017; 7:11905. [PMID: 28928438 PMCID: PMC5605516 DOI: 10.1038/s41598-017-12224-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 09/06/2017] [Indexed: 02/08/2023] Open
Abstract
RIG-I and MDA5 are cytoplasmic viral RNA sensors that belong to the RIG-I-like receptors (RLRs), which induce antiviral innate immune responses, including the production of type I interferon and other pro-inflammatory cytokines. After recognition of viral RNA, the N-terminal caspase activation and recruitment domains (CARDs) of RIG-I and MDA5 bind to a CARD in the MAVS adaptor molecule, resulting in MAVS oligomerization and downstream signaling. To reveal the molecular mechanism of MAVS-dependent signaling, we performed a yeast two-hybrid screening and identified zyxin as a protein that binds to MAVS. Zyxin co-immunoprecipitated with MAVS in human cells. A proximity ligation assay showed that zyxin and MAVS partly co-localized on mitochondria. Ectopic expression of zyxin augmented MAVS-mediated IFN-β promoter activation, and knockdown of zyxin (ZYX) attenuated the IFN-β promoter activation. Moreover, ZYX knockdown reduced the expression of type I IFN and an interferon-inducible gene after stimulation with polyI:C or influenza A virus RNA. Interestingly, physical interactions between RLRs and MAVS were abrogated by ZYX knockdown. These observations indicate that zyxin serves as a scaffold for the interactions between RLRs and MAVS.
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Affiliation(s)
- Takahisa Kouwaki
- Department of Immunology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Masaaki Okamoto
- Department of Immunology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Hirotake Tsukamoto
- Department of Immunology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Yoshimi Fukushima
- Department of Immunology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Misako Matsumoto
- Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Kita-Ku, Sapporo, 060-8556, Japan
| | - Tsukasa Seya
- Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Kita-Ku, Sapporo, 060-8556, Japan
| | - Hiroyuki Oshiumi
- Department of Immunology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
- JST, PRESTO, 1-1-1- Honjo, Chuo-ku, Kumamoto, 060-8556, Japan.
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52
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Abstract
Proper cellular functionality and homeostasis are maintained by the convergent integration of various signaling cascades, which enable cells to respond to internal and external changes. The Dbf2-related kinases LATS1 and LATS2 (LATS) have emerged as central regulators of cell fate, by modulating the functions of numerous oncogenic or tumor suppressive effectors, including the canonical Hippo effectors YAP/TAZ, the Aurora mitotic kinase family, estrogen signaling and the tumor suppressive transcription factor p53. While the basic functions of the LATS kinase module are strongly conserved over evolution, the genomic duplication event leading to the emergence of two closely related kinases in higher organisms has increased the complexity of this signaling network. Here, we review the LATS1 and LATS2 intrinsic features as well as their reported cellular activities, emphasizing unique characteristics of each kinase. While differential activities between the two paralogous kinases have been reported, many converge to similar pathways and outcomes. Interestingly, the regulatory networks controlling the mRNA expression pattern of LATS1 and LATS2 differ strongly, and may contribute to the differences in protein binding partners of each kinase and in the subcellular locations in which each kinase exerts its functions.
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Affiliation(s)
- Noa Furth
- Department of Molecular Cell Biology, The Weizmann Institute of Science, POB 26, 234 Herzl St., Rehovot 7610001, Israel
| | - Yael Aylon
- Department of Molecular Cell Biology, The Weizmann Institute of Science, POB 26, 234 Herzl St., Rehovot 7610001, Israel
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53
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Eroshkin FM, Zaraisky AG. Mechano-sensitive regulation of gene expression during the embryonic development. Genesis 2017; 55. [PMID: 28236362 DOI: 10.1002/dvg.23026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/06/2017] [Accepted: 02/20/2017] [Indexed: 12/14/2022]
Abstract
Cell movements during embryogenesis produce mechanical tensions that shape the embryo and can also regulate gene expression, thereby affecting cell differentiation. Increasing evidence indicates that mechanosensitive regulation of gene expression plays important roles during embryogenesis by coupling the processes of morphogenesis and differentiation. However, the molecular mechanisms of this phenomenon remain poorly understood. This review focuses on the molecular mechanisms that "translate" mechanical stimuli into gene expression.
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Affiliation(s)
- Fedor M Eroshkin
- Laboratory of Molecular Bases of Embryogenesis, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Andrey G Zaraisky
- Laboratory of Molecular Bases of Embryogenesis, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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54
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Pfleger CM. The Hippo Pathway: A Master Regulatory Network Important in Development and Dysregulated in Disease. Curr Top Dev Biol 2017; 123:181-228. [PMID: 28236967 DOI: 10.1016/bs.ctdb.2016.12.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Hippo Pathway is a master regulatory network that regulates proliferation, cell growth, stemness, differentiation, and cell death. Coordination of these processes by the Hippo Pathway throughout development and in mature organisms in response to diverse external and internal cues plays a role in morphogenesis, in controlling organ size, and in maintaining organ homeostasis. Given the importance of these processes, the Hippo Pathway also plays an important role in organismal health and has been implicated in a variety of diseases including eye disease, cardiovascular disease, neurodegeneration, and cancer. This review will focus on Drosophila reports that identified the core components of the Hippo Pathway revealing specific downstream biological outputs of this complicated network. A brief description of mammalian reports will complement review of the Drosophila studies. This review will also survey upstream regulation of the core components with a focus on feedback mechanisms.
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Affiliation(s)
- Cathie M Pfleger
- The Icahn School of Medicine at Mount Sinai, New York, NY, United States; The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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55
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Keira Y, Wada M, Ishikawa HO. Regulation of Drosophila Development by the Golgi Kinase Four-Jointed. Curr Top Dev Biol 2017; 123:143-179. [DOI: 10.1016/bs.ctdb.2016.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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56
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Finch-Edmondson M, Sudol M. Framework to function: mechanosensitive regulators of gene transcription. Cell Mol Biol Lett 2016; 21:28. [PMID: 28536630 PMCID: PMC5415767 DOI: 10.1186/s11658-016-0028-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/16/2016] [Indexed: 01/06/2023] Open
Abstract
Mechanobiology has shifted our understanding of fundamental cellular and physiological functions. Changes to the stiffness of the extracellular matrix, cell rigidity, or shape of the cell environment were considered in the past to be a consequence of aging or pathological processes. We now understand that these factors can actually be causative biological mediators of cell growth to control organ size. Mechanical cues are known to trigger a relatively fast translocation of specific transcriptional co-factors such as MRTFs, YAP and TAZ from the cytoplasm to the cell nucleus to initiate discrete transcriptional programs. The focus of this review is the molecular mechanisms by which biophysical stimuli that induce changes in cytoplasmic actin dynamics are communicated within cells to elicit gene-specific transcription via nuclear localisation or activation of specialized transcription factors, namely MRTFs and the Hippo pathway effectors YAP and TAZ. We propose here that MRTFs, YAP and TAZ closely collaborate as mechano-effectors.
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Affiliation(s)
- Megan Finch-Edmondson
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore.,Department of Physiology, National University of Singapore, Yong Loo Lin School of Medicine, 2 Medical Drive, 117597 Singapore, Singapore
| | - Marius Sudol
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore.,Department of Physiology, National University of Singapore, Yong Loo Lin School of Medicine, 2 Medical Drive, 117597 Singapore, Singapore
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57
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Pan Y, Heemskerk I, Ibar C, Shraiman BI, Irvine KD. Differential growth triggers mechanical feedback that elevates Hippo signaling. Proc Natl Acad Sci U S A 2016; 113:E6974-E6983. [PMID: 27791172 PMCID: PMC5111668 DOI: 10.1073/pnas.1615012113] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mechanical stress can influence cell proliferation in vitro, but whether it makes a significant contribution to growth control in vivo, and how it is modulated and experienced by cells within developing tissues, has remained unclear. Here we report that differential growth reduces cytoskeletal tension along cell junctions within faster-growing cells. We propose a theoretical model to explain the observed reduction of tension within faster-growing clones, supporting it by computer simulations based on a generalized vertex model. This reduced tension modulates a biomechanical Hippo pathway, decreasing recruitment of Ajuba LIM protein and the Hippo pathway kinase Warts, and decreasing the activity of the growth-promoting transcription factor Yorkie. These observations provide a specific mechanism for a mechanical feedback that contributes to evenly distributed growth, and we show that genetically suppressing mechanical feedback alters patterns of cell proliferation in the developing Drosophila wing. By providing experimental support for the induction of mechanical stress by differential growth, and a molecular mechanism linking this stress to the regulation of growth in developing organs, our results confirm and extend the mechanical feedback hypothesis.
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Affiliation(s)
- Yuanwang Pan
- Howard Hughes Medical Institute, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854
| | - Idse Heemskerk
- Kavli Institute of Theoretical Physics, University of California, Santa Barbara, CA 93101
| | - Consuelo Ibar
- Howard Hughes Medical Institute, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854
| | - Boris I Shraiman
- Kavli Institute of Theoretical Physics, University of California, Santa Barbara, CA 93101
| | - Kenneth D Irvine
- Howard Hughes Medical Institute, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854;
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58
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Misra JR, Irvine KD. Vamana Couples Fat Signaling to the Hippo Pathway. Dev Cell 2016; 39:254-266. [PMID: 27746048 DOI: 10.1016/j.devcel.2016.09.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 08/09/2016] [Accepted: 09/15/2016] [Indexed: 01/08/2023]
Abstract
The protocadherins Dachsous and Fat initiate a signaling pathway that controls growth and planar cell polarity by regulating the membrane localization of the atypical myosin Dachs. How Dachs is regulated by Fat signaling has remained unclear. Here we identify the vamana gene as playing a crucial role in regulating membrane localization of Dachs and in linking Fat and Dachsous to Dachs regulation. Vamana, an SH3-domain-containing protein, physically associates with and co-localizes with Dachs and promotes its membrane localization. Vamana also associates with the Dachsous intracellular domain and with a region of the Fat intracellular domain that is essential for controlling Hippo signaling and levels of Dachs. Epistasis experiments, structure-function analysis, and physical interaction experiments argue that Fat negatively regulates Dachs in a Vamana-dependent process. Our findings establish Vamana as a crucial component of the Dachsous-Fat pathway that transmits Fat signaling by regulating Dachs.
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Affiliation(s)
- Jyoti R Misra
- Department of Molecular Biology and Biochemistry, Howard Hughes Medical Institute, Waksman Institute, Rutgers University, Piscataway NJ 08854, USA
| | - Kenneth D Irvine
- Department of Molecular Biology and Biochemistry, Howard Hughes Medical Institute, Waksman Institute, Rutgers University, Piscataway NJ 08854, USA.
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59
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Zhang Y, Wang X, Matakatsu H, Fehon R, Blair SS. The novel SH3 domain protein Dlish/CG10933 mediates fat signaling in Drosophila by binding and regulating Dachs. eLife 2016; 5. [PMID: 27692068 PMCID: PMC5047748 DOI: 10.7554/elife.16624] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 09/15/2016] [Indexed: 01/07/2023] Open
Abstract
Much of the Hippo and planar cell polarity (PCP) signaling mediated by the Drosophila protocadherin Fat depends on its ability to change the subcellular localization, levels and activity of the unconventional myosin Dachs. To better understand this process, we have performed a structure-function analysis of Dachs, and used this to identify a novel and important mediator of Fat and Dachs activities, a Dachs-binding SH3 protein we have named Dlish. We found that Dlish is regulated by Fat and Dachs, that Dlish also binds Fat and the Dachs regulator Approximated, and that Dlish is required for Dachs localization, levels and activity in both wild type and fat mutant tissue. Our evidence supports dual roles for Dlish. Dlish tethers Dachs to the subapical cell cortex, an effect partly mediated by the palmitoyltransferase Approximated under the control of Fat. Conversely, Dlish promotes the Fat-mediated degradation of Dachs. DOI:http://dx.doi.org/10.7554/eLife.16624.001
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Affiliation(s)
- Yifei Zhang
- Department of Zoology, University of Wisconsin-Madison, Madison, United States
| | - Xing Wang
- Department of Zoology, University of Wisconsin-Madison, Madison, United States
| | - Hitoshi Matakatsu
- Department of Zoology, University of Wisconsin-Madison, Madison, United States.,Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, United States
| | - Richard Fehon
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, United States
| | - Seth S Blair
- Department of Zoology, University of Wisconsin-Madison, Madison, United States
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60
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Jahanshahi M, Hsiao K, Jenny A, Pfleger CM. The Hippo Pathway Targets Rae1 to Regulate Mitosis and Organ Size and to Feed Back to Regulate Upstream Components Merlin, Hippo, and Warts. PLoS Genet 2016; 12:e1006198. [PMID: 27494403 PMCID: PMC4975479 DOI: 10.1371/journal.pgen.1006198] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/24/2016] [Indexed: 12/31/2022] Open
Abstract
Hippo signaling acts as a master regulatory pathway controlling growth, proliferation, and apoptosis and also ensures that variations in proliferation do not alter organ size. How the pathway coordinates restricting proliferation with organ size control remains a major unanswered question. Here we identify Rae1 as a highly-conserved target of the Hippo Pathway integrating proliferation and organ size. Genetic and biochemical studies in Drosophila cells and tissues and in mammalian cells indicate that Hippo signaling promotes Rae1 degradation downstream of Warts/Lats. In proliferating cells, Rae1 loss restricts cyclin B levels and organ size while Rae1 over-expression increases cyclin B levels and organ size, similar to Hippo Pathway over-activation or loss-of-function, respectively. Importantly, Rae1 regulation by the Hippo Pathway is crucial for its regulation of cyclin B and organ size; reducing Rae1 blocks cyclin B accumulation and suppresses overgrowth caused by Hippo Pathway loss. Surprisingly, in addition to suppressing overgrowth, reducing Rae1 also compromises survival of epithelial tissue overgrowing due to loss of Hippo signaling leading to a tissue “synthetic lethality” phenotype. Excitingly, Rae1 plays a highly conserved role to reduce the levels and activity of the Yki/YAP oncogene. Rae1 increases activation of the core kinases Hippo and Warts and plays a post-transcriptional role to increase the protein levels of the Merlin, Hippo, and Warts components of the pathway; therefore, in addition to Rae1 coordinating organ size regulation with proliferative control, we propose that Rae1 also acts in a feedback circuit to regulate pathway homeostasis. Exquisite control of organ size is critical during animal development and its loss results in pathological conditions. The Hippo Tumor Suppressor Pathway coordinates regulation of proliferation, growth, apoptosis, and autophagy to determine and maintain precise control of organ size. However, the genes responsible for Hippo-mediated regulation of mitosis or coordination of proliferation within organ size control have evaded characterization. Here, we describe Rae1, an essential WD-repeat containing protein, as a new organ size regulator. By genetic analysis, we show that Rae1 acts downstream of the Hippo Pathway to regulate mitotic cyclins and organ size. In contexts where organ size control is lost by compromised Hippo signaling, we show that there is a requirement for Rae1 that is distinct from the requriement for Yki: reducing Yki levels causes suppression of overgrowth, while reducing Rae1 levels dramatically compromises the survival of Hippo-deficient tissue. Lastly, our studies of Rae1 uncovered a potential post-transcriptional feedback loop that reinforces Yorkie-mediated transcriptional feedback for the Hippo Pathway.
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Affiliation(s)
- Maryam Jahanshahi
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Kuangfu Hsiao
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Neuroscience, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Andreas Jenny
- Department of Developmental and Molecular Biology and Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Cathie M. Pfleger
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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61
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Huang Z, Zhang L, Chen Y, Zhang H, Yu C, Zhou F, Zhang Z, Jiang L, Li R, Ma J, Li Z, Lai Y, Lin T, Zhao X, Zhang Q, Zhang B, Ye Z, Liu S, Wang W, Liang X, Liao R, Shi W. RhoA deficiency disrupts podocyte cytoskeleton and induces podocyte apoptosis by inhibiting YAP/dendrin signal. BMC Nephrol 2016; 17:66. [PMID: 27389190 PMCID: PMC4936208 DOI: 10.1186/s12882-016-0287-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 06/14/2016] [Indexed: 01/19/2023] Open
Abstract
Background Podocyte apoptosis is a major mechanism that leads to proteinuria in many kidney diseases. However, the concert mechanisms that cause podocyte apoptosis in these kidney diseases are not fully understood. RhoA is one of Rho GTPases that has been well studied and plays a key role in regulating cytoskeletal architecture. Previous study showed that insufficient RhoA could result in rat aortic smooth muscle cell apoptosis. However, whether RhoA is involved in podocyte apoptosis remains unknown. Methods Culture podocytes were treated with LPS, ADR or siRNA for 48 h before harvest. Subcellular immunoblotting, qRT-PCR, immunofluorescence and flow cytometry were used to exam the expression and function of RhoA or YAP in podocytes. Results We found that the expression of RhoA and its activity were significantly decreased in LPS or ADR-injured podocytes, accompanying loss of stress fibers and increased cell apoptosis. Knocking down RhoA or its downstream effector mDia expression by siRNA also caused loss of stress fibers and podocyte apoptosis. Moreover, our results further demonstrated that RhoA deficiency could reduce the mRNA and protein expression of YAP, which had been regarded as an anti-apoptosis protein in podocyte. Silenced dendrin expression significantly abolished RhoA, mDia or YAP deficiency-induced podocyte apoptosis. Conclusion RhoA deficiency could disrupt podocyte cytoskeleton and induce podocyte apoptosis by inhibiting YAP/dendrin signal. RhoA/mDia/YAP/dendrin signal pathway may potentially play an important role in regulating podocyte apoptosis. Maintaining necessary RhoA would be one potent way to prevent proteinuria kidney diseases.
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Affiliation(s)
- Zongshun Huang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China.,Southern Medical University, Guangzhou, Guangdong, China
| | - Li Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Yuanhan Chen
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Hong Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Chunping Yu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Fangjian Zhou
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China.,Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Zhiling Zhang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China.,Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Lijuan Jiang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China.,Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Ruizhao Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Jianchao Ma
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Zhuo Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Yuxiong Lai
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Ting Lin
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Xinchen Zhao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Qianmei Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Bin Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Zhiming Ye
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Shuangxin Liu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Wenjian Wang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Xinling Liang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Ruyi Liao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China
| | - Wei Shi
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080, China.
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62
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Feng X, Liu P, Zhou X, Li MT, Li FL, Wang Z, Meng Z, Sun YP, Yu Y, Xiong Y, Yuan HX, Guan KL. Thromboxane A2 Activates YAP/TAZ Protein to Induce Vascular Smooth Muscle Cell Proliferation and Migration. J Biol Chem 2016; 291:18947-58. [PMID: 27382053 PMCID: PMC5009267 DOI: 10.1074/jbc.m116.739722] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 01/12/2023] Open
Abstract
The thromboxane A2 receptor (TP) has been implicated in restenosis after vascular injury, which induces vascular smooth muscle cell (VSMC) migration and proliferation. However, the mechanism for this process is largely unknown. In this study, we report that TP signaling induces VSMC migration and proliferation through activating YAP/TAZ, two major downstream effectors of the Hippo signaling pathway. The TP-specific agonists [1S-[1α,2α(Z),3β(1E,3S*),4 α]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid (I-BOP) and 9,11-dideoxy-9α,11α-methanoepoxy-prosta-5Z,13E-dien-1-oic acid (U-46619) induce YAP/TAZ activation in multiple cell lines, including VSMCs. YAP/TAZ activation induced by I-BOP is blocked by knockout of the receptor TP or knockdown of the downstream G proteins Gα12/13 Moreover, Rho inhibition or actin cytoskeleton disruption prevents I-BOP-induced YAP/TAZ activation. Importantly, TP activation promotes DNA synthesis and cell migration in VSMCs in a manner dependent on YAP/TAZ. Taken together, thromboxane A2 signaling activates YAP/TAZ to promote VSMC migration and proliferation, indicating YAP/TAZ as potential therapeutic targets for cardiovascular diseases.
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Affiliation(s)
- Xu Feng
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Peng Liu
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Xin Zhou
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Meng-Tian Li
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Fu-Long Li
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zhen Wang
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zhipeng Meng
- the Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, California 92130
| | - Yi-Ping Sun
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Ying Yu
- the Key Laboratory of Food Safety Research, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Yue Xiong
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China, the Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Hai-Xin Yuan
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China,
| | - Kun-Liang Guan
- From the Key Laboratory of Molecular Medicine of the Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China, the Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, California 92130,
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Fallahi E, O'Driscoll NA, Matallanas D. The MST/Hippo Pathway and Cell Death: A Non-Canonical Affair. Genes (Basel) 2016; 7:genes7060028. [PMID: 27322327 PMCID: PMC4929427 DOI: 10.3390/genes7060028] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 01/06/2023] Open
Abstract
The MST/Hippo signalling pathway was first described over a decade ago in Drosophila melanogaster and the core of the pathway is evolutionary conserved in mammals. The mammalian MST/Hippo pathway regulates organ size, cell proliferation and cell death. In addition, it has been shown to play a central role in the regulation of cellular homeostasis and it is commonly deregulated in human tumours. The delineation of the canonical pathway resembles the behaviour of the Hippo pathway in the fly where the activation of the core kinases of the pathway prevents the proliferative signal mediated by the key effector of the pathway YAP. Nevertheless, several lines of evidence support the idea that the mammalian MST/Hippo pathway has acquired new features during evolution, including different regulators and effectors, crosstalk with other essential signalling pathways involved in cellular homeostasis and the ability to actively trigger cell death. Here we describe the current knowledge of the mechanisms that mediate MST/Hippo dependent cell death, especially apoptosis. We include evidence for the existence of complex signalling networks where the core proteins of the pathway play a central role in controlling the balance between survival and cell death. Finally, we discuss the possible involvement of these signalling networks in several human diseases such as cancer, diabetes and neurodegenerative disorders.
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Affiliation(s)
- Emma Fallahi
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland. emma.fallahi---
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland. emma.fallahi---
| | - Niamh A O'Driscoll
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland.
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | - David Matallanas
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland.
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.
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64
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Sun S, Irvine KD. Cellular Organization and Cytoskeletal Regulation of the Hippo Signaling Network. Trends Cell Biol 2016; 26:694-704. [PMID: 27268910 DOI: 10.1016/j.tcb.2016.05.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/29/2016] [Accepted: 05/10/2016] [Indexed: 01/12/2023]
Abstract
The Hippo signaling network integrates diverse upstream signals to control cell fate decisions and regulate organ growth. Recent studies have provided new insights into the cellular organization of Hippo signaling, its relationship to cell-cell junctions, and how the cytoskeleton modulates Hippo signaling. Cell-cell junctions serve as platforms for Hippo signaling by localizing scaffolding proteins that interact with core components of the pathway. Interactions of Hippo pathway components with cell-cell junctions and the cytoskeleton also suggest potential mechanisms for the regulation of the pathway by cell contact and cell polarity. As our understanding of the complexity of Hippo signaling increases, a future challenge will be to understand how the diverse inputs into the pathway are integrated and to define their respective contributions in vivo.
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Affiliation(s)
- Shuguo Sun
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA
| | - Kenneth D Irvine
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
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65
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Elbediwy A, Vincent-Mistiaen ZI, Spencer-Dene B, Stone RK, Boeing S, Wculek SK, Cordero J, Tan EH, Ridgway R, Brunton VG, Sahai E, Gerhardt H, Behrens A, Malanchi I, Sansom OJ, Thompson BJ. Integrin signalling regulates YAP and TAZ to control skin homeostasis. Development 2016; 143:1674-87. [PMID: 26989177 PMCID: PMC4874484 DOI: 10.1242/dev.133728] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/09/2016] [Indexed: 12/14/2022]
Abstract
The skin is a squamous epithelium that is continuously renewed by a population of basal layer stem/progenitor cells and can heal wounds. Here, we show that the transcription regulators YAP and TAZ localise to the nucleus in the basal layer of skin and are elevated upon wound healing. Skin-specific deletion of both YAP and TAZ in adult mice slows proliferation of basal layer cells, leads to hair loss and impairs regeneration after wounding. Contact with the basal extracellular matrix and consequent integrin-Src signalling is a key determinant of the nuclear localisation of YAP/TAZ in basal layer cells and in skin tumours. Contact with the basement membrane is lost in differentiating daughter cells, where YAP and TAZ become mostly cytoplasmic. In other types of squamous epithelia and squamous cell carcinomas, a similar control mechanism is present. By contrast, columnar epithelia differentiate an apical domain that recruits CRB3, Merlin (also known as NF2), KIBRA (also known as WWC1) and SAV1 to induce Hippo signalling and retain YAP/TAZ in the cytoplasm despite contact with the basal layer extracellular matrix. When columnar epithelial tumours lose their apical domain and become invasive, YAP/TAZ becomes nuclear and tumour growth becomes sensitive to the Src inhibitor Dasatinib.
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Affiliation(s)
- Ahmed Elbediwy
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | | | | | - Richard K Stone
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Stefan Boeing
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Stefanie K Wculek
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Julia Cordero
- The Beatson Institute, Switchback Rd, Bearsden, Glasgow G61 1BD, UK
| | - Ee H Tan
- The Beatson Institute, Switchback Rd, Bearsden, Glasgow G61 1BD, UK
| | - Rachel Ridgway
- Edinburgh Cancer Research Centre, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Val G Brunton
- Edinburgh Cancer Research Centre, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Erik Sahai
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Holger Gerhardt
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Axel Behrens
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Ilaria Malanchi
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Owen J Sansom
- The Beatson Institute, Switchback Rd, Bearsden, Glasgow G61 1BD, UK
| | - Barry J Thompson
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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66
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Elbediwy A, Vincent-Mistiaen ZI, Thompson BJ. YAP and TAZ in epithelial stem cells: A sensor for cell polarity, mechanical forces and tissue damage. Bioessays 2016; 38:644-53. [PMID: 27173018 PMCID: PMC5031209 DOI: 10.1002/bies.201600037] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The YAP/TAZ family of transcriptional co‐activators drives cell proliferation in epithelial tissues and cancers. Yet, how YAP and TAZ are physiologically regulated remains unclear. Here we review recent reports that YAP and TAZ act primarily as sensors of epithelial cell polarity, being inhibited when cells differentiate an apical membrane domain, and being activated when cells contact the extracellular matrix via their basal membrane domain. Apical signalling occurs via the canonical Crumbs/CRB‐Hippo/MST‐Warts/LATS kinase cascade to phosphorylate and inhibit YAP/TAZ. Basal signalling occurs via Integrins and Src family kinases to phosphorylate and activate YAP/TAZ. Thus, YAP/TAZ is localised to the nucleus in basal stem/progenitor cells and cytoplasm in differentiated squamous cells or columnar cells. In addition, other signals such as mechanical forces, tissue damage and possibly receptor tyrosine kinases (RTKs) can influence MST‐LATS or Src family kinase activity to modulate YAP/TAZ activity.
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Affiliation(s)
- Ahmed Elbediwy
- Epithelial Biology Laboratory, Francis Crick Institute, London, UK
| | | | - Barry J Thompson
- Epithelial Biology Laboratory, Francis Crick Institute, London, UK
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67
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Urdy S, Goudemand N, Pantalacci S. Looking Beyond the Genes: The Interplay Between Signaling Pathways and Mechanics in the Shaping and Diversification of Epithelial Tissues. Curr Top Dev Biol 2016; 119:227-90. [PMID: 27282028 DOI: 10.1016/bs.ctdb.2016.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The core of Evo-Devo lies in the intuition that the way tissues grow during embryonic development, the way they sustain their structure and function throughout lifetime, and the way they evolve are closely linked. Epithelial tissues are ubiquitous in metazoans, covering the gut and internal branched organs, as well as the skin and its derivatives (ie, teeth). Here, we discuss in vitro, in vivo, and in silico studies on epithelial tissues to illustrate the conserved, dynamical, and complex aspects of their development. We then explore the implications of the dynamical and nonlinear nature of development on the evolution of their size and shape at the phenotypic and genetic levels. In rare cases, when the interplay between signaling and mechanics is well understood at the cell level, it is becoming clear that the structure of development leads to covariation of characters, an integration which in turn provides some predictable structure to evolutionary changes. We suggest that such nonlinear systems are prone to genetic drift, cryptic genetic variation, and context-dependent mutational effects. We argue that experimental and theoretical studies at the cell level are critical to our understanding of the phenotypic and genetic evolution of epithelial tissues, including carcinomas.
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Affiliation(s)
- S Urdy
- University of Zürich, Institute of Physics, Zürich, Switzerland.
| | - N Goudemand
- Univ Lyon, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Institut de Génomique Fonctionnelle de Lyon, UMR 5242, Lyon Cedex 07, France
| | - S Pantalacci
- Univ Lyon, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Laboratory of Biology and Modelling of the Cell, UMR 5239, INSERM U1210, Lyon Cedex 07, France
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68
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Saavedra P, Brittle A, Palacios IM, Strutt D, Casal J, Lawrence PA. Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila. Biol Open 2016; 5:397-408. [PMID: 26935392 PMCID: PMC4890672 DOI: 10.1242/bio.017152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 02/01/2016] [Indexed: 11/20/2022] Open
Abstract
The epidermal patterns of all three larval instars (L1-L3) ofDrosophilaare made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults.
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Affiliation(s)
- Pedro Saavedra
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 2EJ, UK
| | - Amy Brittle
- Department of Biomedical Science, The University of Sheffield, Sheffield S10 2TN, UK
| | - Isabel M Palacios
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 2EJ, UK
| | - David Strutt
- Department of Biomedical Science, The University of Sheffield, Sheffield S10 2TN, UK
| | - José Casal
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 2EJ, UK
| | - Peter A Lawrence
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 2EJ, UK
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69
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Ma B, Cheng H, Gao R, Mu C, Chen L, Wu S, Chen Q, Zhu Y. Zyxin-Siah2-Lats2 axis mediates cooperation between Hippo and TGF-β signalling pathways. Nat Commun 2016; 7:11123. [PMID: 27030211 PMCID: PMC4821889 DOI: 10.1038/ncomms11123] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 02/18/2016] [Indexed: 12/21/2022] Open
Abstract
The evolutionarily conserved Hippo pathway is a regulator that controls organ size, cell growth and tissue homeostasis. Upstream signals of the Hippo pathway have been widely studied, but how microenvironmental factors coordinately regulate this pathway remains unclear. In this study, we identify LIM domain protein Zyxin, as a scaffold protein, that in response to hypoxia and TGF-β stimuli, forms a ternary complex with Lats2 and Siah2 and stabilizes their interaction. This interaction facilitates Lats2 ubiquitination and degradation, Yap dephosphorylation and subsequently activation. We show that Zyxin is required for TGF-β and hypoxia-induced Lats2 downregulation and deactivation of Hippo signalling in MDA-MB-231 cells. Depletion of Zyxin impairs the capability of cell migration, proliferation and tumourigenesis in a xenograft model. Zyxin is upregulated in human breast cancer and positively correlates with histological stages and metastasis. Our study demonstrates that Zyxin-Lats2–Siah2 axis may serve as a potential therapeutic target in cancer treatment. Hippo and TGF-β are crucial signalling pathways involved in the development of various types of tumours. Here, the authors demonstrate that TGF-β can directly regulate Hippo pathway through the stabilization of the scaffold protein Zyxin, which forms a ternary complex with Siah2 and Lats2 promoting Lats2 degradation and YAP activation.
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Affiliation(s)
- Biao Ma
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hongcheng Cheng
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ruize Gao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Chenglong Mu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ling Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Shian Wu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Quan Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China.,State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yushan Zhu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China
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70
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Han MKL, de Rooij J. Converging and Unique Mechanisms of Mechanotransduction at Adhesion Sites. Trends Cell Biol 2016; 26:612-623. [PMID: 27036655 DOI: 10.1016/j.tcb.2016.03.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 12/31/2022]
Abstract
The molecular mechanisms by which physical forces control tissue development are beginning to be elucidated. Sites of adhesion between both cells and the extracellular environment [extracellular matrix (ECM) or neighboring cells] contain protein complexes capable of sensing fluctuations in tensile forces. Tension-dependent changes in the dynamics and composition of these complexes mark the transformation of physical input into biochemical signals that defines mechanotransduction. It is becoming apparent that, although the core constituents of these different adhesions are distinct, principles and proteins involved in mechanotransduction are conserved. Here, we discuss the current knowledge of overlapping and distinct aspects of mechanotransduction between integrin and cadherin adhesion complexes.
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Affiliation(s)
- Mitchell K L Han
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Johan de Rooij
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
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71
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Poon CLC, Mitchell KA, Kondo S, Cheng LY, Harvey KF. The Hippo Pathway Regulates Neuroblasts and Brain Size in Drosophila melanogaster. Curr Biol 2016; 26:1034-42. [PMID: 26996505 DOI: 10.1016/j.cub.2016.02.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 12/22/2015] [Accepted: 02/02/2016] [Indexed: 12/12/2022]
Abstract
A key question in developmental neurobiology is how neural stem cells regulate their proliferative potential and cellular diversity and thus specify the overall size of the brain. Drosophila melanogaster neural stem cells (neuroblasts) are known to regulate their ability to self-renew by asymmetric cell division and produce different types of neurons and glia through sequential expression of temporal transcription factors [1]. Here, we show that the conserved Hippo pathway, a key regulator of epithelial organ size [2-4], restricts neuroblast proliferative potential and neuronal cell number to regulate brain size. The inhibition of Hippo pathway activity via depletion of the core kinases Tao-1, Hippo, or Warts regulates several key characteristics of neuroblasts during postembryonic neurogenesis. The Hippo pathway is required to maintain timely entry and exit from neurogenesis by regulating both neuroblast reactivation from quiescence and the time at which neuroblasts undergo terminal differentiation. Further, it restricts neuroblast cell-cycle speed, specifies cell size, and alters the proportion of neuron types generated during postembryonic neurogenesis. Collectively, deregulation of Hippo signaling in neuroblasts causes a substantial increase in overall brain size. We show that these effects are mediated via the key downstream transcription co-activator Yorkie and that, indeed, Yorkie overexpression in neuroblasts is sufficient to cause brain overgrowth. These studies reveal a novel mechanism that controls stem cell proliferative potential during postembryonic neurogenesis to regulate brain size.
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Affiliation(s)
- Carole L C Poon
- Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Katrina A Mitchell
- Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Shu Kondo
- Laboratory of Invertebrate Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, Japan
| | - Louise Y Cheng
- Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia.
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72
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Epithelial tricellular junctions act as interphase cell shape sensors to orient mitosis. Nature 2016; 530:495-8. [PMID: 26886796 PMCID: PMC5450930 DOI: 10.1038/nature16970] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 01/05/2016] [Indexed: 12/24/2022]
Abstract
The orientation of cell division along the interphase cell long-axis, the century old Hertwig’s rule, has profound roles in tissue proliferation, morphogenesis, architecture and mechanics1,2. In epithelial tissues, the shape of the interphase cell is influenced by cell adhesion, mechanical stress, neighbour topology, and planar polarity pathways3–12. At mitosis, epithelial cells usually round up to ensure faithful chromosome segregation and to promote morphogenesis1. The mechanisms underlying interphase cell shape sensing in tissues are therefore unknown. We found that in Drosophila epithelia, tricellular junctions (TCJ) localize microtubule force generators, orienting cell division via the Dynein associated protein Mud independently of the classical Pins/Gαi pathway. Moreover, as cells round up during mitosis, TCJs serve as spatial landmarks, encoding information about interphase cell shape anisotropy to orient division in the rounded mitotic cell. Finally, experimental and simulation data show that shape and mechanical strain sensing by the TCJ emerge from a general geometric property of TCJ distributions in epithelial tissues. Thus, in addition to their function as epithelial barrier structures, TCJs serve as polarity cues promoting geometry and mechanical sensing in epithelial tissues.
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73
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A Drosophila RNAi library modulates Hippo pathway-dependent tissue growth. Nat Commun 2016; 7:10368. [PMID: 26758424 PMCID: PMC4735554 DOI: 10.1038/ncomms10368] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/04/2015] [Indexed: 01/06/2023] Open
Abstract
Libraries of transgenic Drosophila melanogaster carrying RNA interference (RNAi) constructs have been used extensively to perform large-scale functional genetic screens in vivo. For example, RNAi screens have facilitated the discovery of multiple components of the Hippo pathway, an evolutionarily conserved growth-regulatory network. Here we investigate an important technical limitation with the widely used VDRC KK RNAi collection. We find that approximately 25% of VDRC KK RNAi lines cause false-positive enhancement of the Hippo pathway, owing to ectopic expression of the Tiptop transcription factor. Of relevance to the broader Drosophila community, ectopic tiptop (tio) expression can also cause organ malformations and mask phenotypes such as organ overgrowth. To enhance the use of the VDRC KK RNAi library, we have generated a D. melanogaster strain that will allow researchers to test, in a single cross, whether their genetic screen of interest will be affected by ectopic tio expression. Drosophila RNAi libraries are commonly used to perform large-scale functional genetics screens in vivo. Here the authors find that a subset of lines from the VDRC KK RNAi line cause false-positive enhancement of the Hippo pathway, and provide a strain that can test whether a genetic screen of interest will be affected by this technical artefact.
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74
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Bosveld F, Guirao B, Wang Z, Rivière M, Bonnet I, Graner F, Bellaïche Y. Modulation of junction tension by tumor-suppressors and proto-oncogenes regulates cell-cell contacts. Development 2016; 143:623-34. [DOI: 10.1242/dev.127993] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 01/07/2016] [Indexed: 12/26/2022]
Abstract
Tumor-suppressor and proto-oncogenes play critical roles in tissue proliferation. Furthermore, deregulation of their functions is deleterious to tissue architecture and can result in the sorting of somatic rounded clones minimizing their contact with surrounding wild-type (wt) cells. Defects in somatic clones shape correlate with defects in proliferation, cell affinity, cell-cell adhesion, oriented cell division and cortical elasticity. Combining genetics, live-imaging, laser ablation and computer simulations, we aim to analyze whether distinct or similar mechanisms can account for the common role of tumor-suppressor and proto-oncogenes in cell-cell contact regulation. In Drosophila epithelia, Fat (Ft) and Dachsous (Ds) tumor-suppressors regulate cell proliferation, tissue morphogenesis, planar cell polarity and junction tension. By analyzing the time evolution of ft mutant cells and clones, we show that ft clones reduce their cell-cell contact with surrounding wt tissue in the absence of concomitant cell divisions and over-proliferation. This contact reduction depends on opposite changes of junction tensions in the clone bulk and its boundary with neighboring wt tissue. More generally, either clone bulk or boundary junction tensions is modulated by the activation of Yorkie, Myc and Ras yielding similar contact reductions with wt cells. Together our data highlight mechanical roles for proto-oncogene and tumor-suppressor pathways in cell-cell interactions.
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Affiliation(s)
- Floris Bosveld
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Boris Guirao
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Zhimin Wang
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - Mathieu Rivière
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
- Present address: Matière et Systèmes Complexes, Université Paris Diderot, CNRS UMR 7057, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Isabelle Bonnet
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
- Present address: Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR 168, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - François Graner
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
- Present address: Matière et Systèmes Complexes, Université Paris Diderot, CNRS UMR 7057, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Yohanns Bellaïche
- Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue d'Ulm, 75248 Paris Cedex 05, France
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75
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Abstract
The mammalian MST kinase family, which is related to the Hippo kinase in Drosophila melanogaster, includes five related proteins: MST1 (also called STK4), MST2 (also called STK3), MST3 (also called STK24), MST4, and YSK1 (also called STK25 or SOK1). MST kinases are emerging as key signaling molecules that influence cell proliferation, organ size, cell migration, and cell polarity. Here we review the regulation and function of these kinases in normal physiology and pathologies, including cancer, endothelial malformations, and autoimmune disease.
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Affiliation(s)
| | - Erik Sahai
- The Francis Crick Institute, London WC2A 3LY, England, UK
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Dupont S. Role of YAP/TAZ in cell-matrix adhesion-mediated signalling and mechanotransduction. Exp Cell Res 2015; 343:42-53. [PMID: 26524510 DOI: 10.1016/j.yexcr.2015.10.034] [Citation(s) in RCA: 305] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 10/29/2015] [Indexed: 12/12/2022]
Abstract
Signalling from the extracellular matrix (ECM) is a fundamental cellular input that sustains proliferation, opposes cell death and regulates differentiation. Through integrins, cells perceive both the chemical composition and physical properties of the ECM. In particular, cell behaviour is profoundly influenced by the mechanical elasticity or stiffness of the ECM, which regulates the ability of cells to develop forces through their contractile actomyosin cytoskeleton and to mature focal adhesions. This mechanosensing ability affects fundamental cellular functions, such that alterations of ECM stiffness is nowadays considered not a simple consequence of pathology, but a causative input driving aberrant cell behaviours. We here discuss recent advances on how mechanical signals intersect nuclear transcription and in particular the activity of YAP/TAZ transcriptional coactivators, known downstream transducers of the Hippo pathway and important effectors of ECM mechanical cues.
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Affiliation(s)
- Sirio Dupont
- Department of Molecular Medicine, University of Padua Medical School, via Bassi 58/B, 35131 Padua, Italy.
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77
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Ambegaonkar AA, Irvine KD. Coordination of planar cell polarity pathways through Spiny-legs. eLife 2015; 4. [PMID: 26505959 PMCID: PMC4764577 DOI: 10.7554/elife.09946] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/23/2015] [Indexed: 12/11/2022] Open
Abstract
Morphogenesis and physiology of tissues and organs requires planar cell polarity (PCP) systems that orient and coordinate cells and their behaviors, but the relationship between PCP systems has been controversial. We have characterized how the Frizzled and Dachsous-Fat PCP systems are connected through the Spiny-legs isoform of the Prickle-Spiny-legs locus. Two different components of the Dachsous-Fat system, Dachsous and Dachs, can each independently interact with Spiny-legs and direct its localization in vivo. Through characterization of the contributions of Prickle, Spiny-legs, Dachsous, Fat, and Dachs to PCP in the Drosophila wing, eye, and abdomen, we define where Dachs-Spiny-legs and Dachsous-Spiny-legs interactions contribute to PCP, and provide a new understanding of the orientation of polarity and the basis of PCP phenotypes. Our results support the direct linkage of PCP systems through Sple in specific locales, while emphasizing that cells can be subject to and must ultimately resolve distinct, competing PCP signals. DOI:http://dx.doi.org/10.7554/eLife.09946.001 Animals have many asymmetric organs. Wings, for example, are aerodynamically shaped and have a clear front, back, top and bottom, and even additions to these organs, such as feathers on the wing, often need to be oriented in a specific manner. This kind of orientation arises when cells divide and grow asymmetrically in a flat plane. The asymmetry is established at the level of single cells when proteins are not equally spread throughout a cell, but rather asymmetrically distributed. Such cells are said to be ‘planar polarized’; and many experiments addressing this so-called planar cell polarity have been conducted in fruit flies, because they can be genetically altered easily. Previous studies have shown that two signaling pathways—called Frizzled and Dachsous-Fat—regulate how individual cells orient themselves within a flat sheet of cells that forms fruit fly’s wing. The two pathways are not independent, but it is unclear how they are linked. In particular, there has been conflicting evidence as to whether the Dachsous-Fat pathway controls the Frizzled pathway or whether the two act in parallel. Now, Ambegaonkar and Irvine have discovered new roles for a protein that is involved in both pathways, called 'Spiny-legs'. This protein was known to be important in the Frizzled pathway, but, when it was tracked with a fluorescent tag in developing wing cells it also accumulated in areas where two proteins that make up part of the Dachsous-Fat pathway were located. Biochemical experiments showed that both of these proteins (which are called Dachs or Dachsous) could physically interact with Spiny-legs. Ambegaonkar and Irvine therefore deleted the genes for Dachs or Dachsous in fruit flies and observed that Spiny-legs no longer organized itself in the proper way, implying that Dachs and Dachsous control where Spiny-legs goes within cells. When this analysis was extended to other fruit fly organs, such as the eyes, Ambegaonkar and Irvine found that Dachsous was more important than Dachs for the correct localization of Spiny-legs. Additionally, the Frizzled and Dachsous-Fat pathways seemed to compete for interactions with Spiny-legs. This connection between the two pathways helps to explain how cells behave when several different signals reach them. It also shows how different organs can reuse conserved components of the pathways to make different end products. Future studies should aim to work out the number of systems that polarize cells and how they are connected in different tissues. DOI:http://dx.doi.org/10.7554/eLife.09946.002
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Affiliation(s)
- Abhijit A Ambegaonkar
- Howard Hughes Medical Institute, Rutgers University, Piscataway, United States.,Waksman Institute of Microbiology, Rutgers University, Piscataway, United States.,Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, United States
| | - Kenneth D Irvine
- Howard Hughes Medical Institute, Rutgers University, Piscataway, United States.,Waksman Institute of Microbiology, Rutgers University, Piscataway, United States.,Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, United States
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78
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Localization of Hippo signalling complexes and Warts activation in vivo. Nat Commun 2015; 6:8402. [PMID: 26420589 PMCID: PMC4598633 DOI: 10.1038/ncomms9402] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/19/2015] [Indexed: 01/20/2023] Open
Abstract
Hippo signalling controls organ growth and cell fate by regulating the activity of the kinase Warts. Multiple Hippo pathway components localize to apical junctions in epithelial cells, but the spatial and functional relationships among components have not been clarified, nor is it known where Warts activation occurs. We report here that Hippo pathway components in Drosophila wing imaginal discs are organized into distinct junctional complexes, including separate distributions for Salvador, Expanded, Warts and Hippo. These complexes are reorganized on Hippo pathway activation, when Warts shifts from associating with its inhibitor Jub to its activator Expanded, and Hippo concentrates at Salvador sites. We identify mechanisms promoting Warts relocalization, and using a phospho-specific antisera and genetic manipulations, identify where Warts activation occurs: at apical junctions where Expanded, Salvador, Hippo and Warts overlap. Our observations define spatial relationships among Hippo signalling components and establish the functional importance of their localization to Warts activation. Components of the Hippo signalling pathway localize to apical junctions in epithelial cells, where they regulate growth in response to mechanical and biochemical cues. Sun et al. show that these proteins are organized into distinct junctional complexes, which reorganize up on Hippo pathway activation.
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79
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A large-scale in vivo RNAi screen to identify genes involved in Notch-mediated follicle cell differentiation and cell cycle switches. Sci Rep 2015. [PMID: 26205122 PMCID: PMC4513280 DOI: 10.1038/srep12328] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
During Drosophila oogenesis, follicle cells sequentially undergo three distinct cell-cycle programs: the mitotic cycle, endocycle, and gene amplification. Notch signaling plays a central role in regulating follicle-cell differentiation and cell-cycle switches; its activation is essential for the mitotic cycle/endocycle (M/E) switch. Cut, a linker between Notch signaling and cell-cycle regulators, is specifically downregulated by Notch during the endocycle stage. To determine how signaling pathways coordinate during the M/E switch and to identify novel genes involved in follicle cell differentiation, we performed an in vivo RNAi screen through induced knockdown of gene expression and examination of Cut expression in follicle cells. We screened 2205 RNAi lines and found 33 genes regulating Cut expression during the M/E switch. These genes were confirmed with the staining of two other Notch signaling downstream factors, Hindsight and Broad, and validated with multiple independent RNAi lines. We applied gene ontology software to find enriched biological meaning and compared our results with other publications to find conserved genes across tissues. Specifically, we found earlier endocycle entry in anterior follicle cells than those in the posterior, identified that the insulin-PI3K pathway participates in the precise M/E switch, and suggested Nejire as a cofactor of Notch signaling during oogenesis.
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80
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Enomoto M, Kizawa D, Ohsawa S, Igaki T. JNK signaling is converted from anti- to pro-tumor pathway by Ras-mediated switch of Warts activity. Dev Biol 2015; 403:162-71. [DOI: 10.1016/j.ydbio.2015.05.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 04/30/2015] [Accepted: 05/02/2015] [Indexed: 02/07/2023]
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Wittkorn E, Sarkar A, Garcia K, Kango-Singh M, Singh A. The Hippo pathway effector Yki downregulates Wg signaling to promote retinal differentiation in the Drosophila eye. Development 2015; 142:2002-13. [PMID: 25977365 DOI: 10.1242/dev.117358] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 04/16/2015] [Indexed: 01/22/2023]
Abstract
The evolutionarily conserved Hippo signaling pathway is known to regulate cell proliferation and maintain tissue homeostasis during development. We found that activation of Yorkie (Yki), the effector of the Hippo signaling pathway, causes separable effects on growth and differentiation of the Drosophila eye. We present evidence supporting a role for Yki in suppressing eye fate by downregulation of the core retinal determination genes. Other upstream regulators of the Hippo pathway mediate this effect of Yki on retinal differentiation. Here, we show that, in the developing eye, Yki can prevent retinal differentiation by blocking morphogenetic furrow (MF) progression and R8 specification. The inhibition of MF progression is due to ectopic induction of Wingless (Wg) signaling and Homothorax (Hth), the negative regulators of eye development. Modulating Wg signaling can modify Yki-mediated suppression of eye fate. Furthermore, ectopic Hth induction due to Yki activation in the eye is dependent on Wg. Last, using Cut (Ct), a marker for the antennal fate, we show that suppression of eye fate by hyperactivation of yki does not change the cell fate (from eye to antenna-specific fate). In summary, we provide the genetic mechanism by which yki plays a role in cell fate specification and differentiation - a novel aspect of Yki function that is emerging from multiple model organisms.
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Affiliation(s)
- Erika Wittkorn
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Ankita Sarkar
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Kristine Garcia
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA
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82
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Young K, Tweedie E, Conley B, Ames J, FitzSimons M, Brooks P, Liaw L, Vary CPH. BMP9 Crosstalk with the Hippo Pathway Regulates Endothelial Cell Matricellular and Chemokine Responses. PLoS One 2015; 10:e0122892. [PMID: 25909848 PMCID: PMC4409298 DOI: 10.1371/journal.pone.0122892] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/24/2015] [Indexed: 12/26/2022] Open
Abstract
Endoglin is a type III TGFβ auxiliary receptor that is upregulated in endothelial cells during angiogenesis and, when mutated in humans, results in the vascular disease hereditary hemorrhagic telangiectasia (HHT). Though endoglin has been implicated in cell adhesion, the underlying molecular mechanisms are still poorly understood. Here we show endoglin expression in endothelial cells regulates subcellular localization of zyxin in focal adhesions in response to BMP9. RNA knockdown of endoglin resulted in mislocalization of zyxin and altered formation of focal adhesions. The mechanotransduction role of focal adhesions and their ability to transmit regulatory signals through binding of the extracellular matrix are altered by endoglin deficiency. BMP/TGFβ transcription factors, SMADs, and zyxin have recently been implicated in a newly emerging signaling cascade, the Hippo pathway. The Hippo transcription coactivator, YAP1 (yes-associated protein 1), has been suggested to play a crucial role in mechanotransduction and cell-cell contact. Identification of BMP9-dependent nuclear localization of YAP1 in response to endoglin expression suggests a mechanism of crosstalk between the two pathways. Suppression of endoglin and YAP1 alters BMP9-dependent expression of YAP1 target genes CCN1 (cysteine-rich 61, CYR61) and CCN2 (connective tissue growth factor, CTGF) as well as the chemokine CCL2 (monocyte chemotactic protein 1, MCP-1). These results suggest a coordinate effect of endoglin deficiency on cell matrix remodeling and local inflammatory responses. Identification of a direct link between the Hippo pathway and endoglin may reveal novel mechanisms in the etiology of HHT.
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Affiliation(s)
- Kira Young
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Eric Tweedie
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
| | - Barbara Conley
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
| | - Jacquelyn Ames
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - MaryLynn FitzSimons
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Peter Brooks
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Lucy Liaw
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Calvin P. H. Vary
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
- * E-mail:
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83
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Gaspar P, Holder MV, Aerne BL, Janody F, Tapon N. Zyxin antagonizes the FERM protein expanded to couple F-actin and Yorkie-dependent organ growth. Curr Biol 2015; 25:679-689. [PMID: 25728696 DOI: 10.1016/j.cub.2015.01.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 12/17/2014] [Accepted: 01/02/2015] [Indexed: 01/15/2023]
Abstract
BACKGROUND Coordinated multicellular growth during development is achieved by the sensing of spatial and nutritional boundaries. The conserved Hippo (Hpo) signaling pathway has been proposed to restrict tissue growth by perceiving mechanical constraints through actin cytoskeleton networks. The actin-associated LIM proteins Zyxin (Zyx) and Ajuba (Jub) have been linked to the control of tissue growth via regulation of Hpo signaling, but the study of Zyx has been hampered by a lack of genetic tools. RESULTS We generated a zyx mutant in Drosophila using TALEN endonucleases and used this to show that Zyx antagonizes the FERM-domain protein Expanded (Ex) to control tissue growth, eye differentiation, and F-actin accumulation. Zyx membrane targeting promotes the interaction between the transcriptional co-activator Yorkie (Yki) and the transcription factor Scalloped (Sd), leading to activation of Yki target gene expression and promoting tissue growth. Finally, we show that Zyx's growth-promoting function is dependent on its interaction with the actin-associated protein Enabled (Ena) via a conserved LPPPP motif and is antagonized by Capping Protein (CP). CONCLUSIONS Our results show that Zyx is a functional antagonist of Ex in growth control and establish a link between actin filament polymerization and Yki activity.
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Affiliation(s)
- Pedro Gaspar
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
| | - Maxine V Holder
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Birgit L Aerne
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Florence Janody
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| | - Nicolas Tapon
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
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84
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85
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Differential regulation of the Hippo pathway by adherens junctions and apical-basal cell polarity modules. Proc Natl Acad Sci U S A 2015; 112:1785-90. [PMID: 25624491 DOI: 10.1073/pnas.1420850112] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Adherens junctions (AJs) and cell polarity complexes are key players in the establishment and maintenance of apical-basal cell polarity. Loss of AJs or basolateral polarity components promotes tumor formation and metastasis. Recent studies in vertebrate models show that loss of AJs or loss of the basolateral component Scribble (Scrib) cause deregulation of the Hippo tumor suppressor pathway and hyperactivation of its downstream effectors Yes-associated protein (YAP) and Transcriptional coactivator with PDZ-binding motif (TAZ). However, whether AJs and Scrib act through the same or independent mechanisms to regulate Hippo pathway activity is not known. Here, we dissect how disruption of AJs or loss of basolateral components affect the activity of the Drosophila YAP homolog Yorkie (Yki) during imaginal disc development. Surprisingly, disruption of AJs and loss of basolateral proteins produced very different effects on Yki activity. Yki activity was cell-autonomously decreased but non-cell-autonomously elevated in tissues where the AJ components E-cadherin (E-cad) or α-catenin (α-cat) were knocked down. In contrast, scrib knockdown caused a predominantly cell-autonomous activation of Yki. Moreover, disruption of AJs or basolateral proteins had different effects on cell polarity and tissue size. Simultaneous knockdown of α-cat and scrib induced both cell-autonomous and non-cell-autonomous Yki activity. In mammalian cells, knockdown of E-cad or α-cat caused nuclear accumulation and activation of YAP without overt effects on Scrib localization and vice versa. Therefore, our results indicate the existence of multiple, genetically separable inputs from AJs and cell polarity complexes into Yki/YAP regulation.
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86
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Zhang H, Li C, Chen H, Wei C, Dai F, Wu H, Dui W, Deng WM, Jiao R. SCF(Slmb) E3 ligase-mediated degradation of Expanded is inhibited by the Hippo pathway in Drosophila. Cell Res 2014; 25:93-109. [PMID: 25522691 DOI: 10.1038/cr.2014.166] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/13/2014] [Accepted: 11/18/2014] [Indexed: 12/12/2022] Open
Abstract
Deregulation of the evolutionarily conserved Hippo pathway has been implicated in abnormal development of animals and in several types of cancer. One mechanism of Hippo pathway regulation is achieved by controlling the stability of its regulatory components. However, the executive E3 ligases that are involved in this process, and how the process is regulated, remain poorly defined. In this study, we identify, through a genetic candidate screen, the SCF(Slmb) E3 ligase as a novel negative regulator of the Hippo pathway in Drosophila imaginal tissues via mediation of the degradation of Expanded (Ex). Mechanistic study shows that Slmb-mediated degradation of Ex is inhibited by the Hippo signaling. Considering the fact that Hippo signaling suppresses the transcription of ex, we propose that the Hippo pathway employs a double security mechanism to ensure fine-tuned homeostasis during development.
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Affiliation(s)
- Hongtao Zhang
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Changqing Li
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China
| | - Hanqing Chen
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Chuanxian Wei
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Fei Dai
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Honggang Wu
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Wen Dui
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100080, China
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, Florida 32304-4295, USA
| | - Renjie Jiao
- 1] State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, the Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China [2] Guangzhou Hoffmann Institute of Immunology, School of Basic Sciences, Guangzhou Medical University, Dongfengxi Road 195, Guangzhou, Guangdong 510182, China
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87
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Del Re DP. The hippo signaling pathway: implications for heart regeneration and disease. Clin Transl Med 2014; 3:27. [PMID: 26932373 PMCID: PMC4884045 DOI: 10.1186/s40169-014-0027-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/22/2014] [Indexed: 12/12/2022] Open
Abstract
Control of cell number and organ size is critical for appropriate development and tissue homeostasis. Studies in both Drosophila and mammals have established the Hippo signaling pathway as an important modulator of organ size and tumorigenesis. Upon activation, this kinase cascade modulates gene expression through the phosphorylation and inhibition of transcription co-activators that are involved in cell proliferation, differentiation, growth and apoptosis. Hippo signaling serves to limit organ size and suppress malignancies, and has been implicated in tissue regeneration following injury. These outcomes highlight the important role that Hippo signaling plays in regulating both physiologic and pathologic processes. In this review, an overview of the signaling pathway will be discussed as well as recent work that has investigated its role in cardiac development, regeneration and disease.
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Affiliation(s)
- Dominic P Del Re
- Cardiovascular Research Institute and Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers Newark, 07103, NJ, USA.
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88
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Gaspar P, Tapon N. Sensing the local environment: actin architecture and Hippo signalling. Curr Opin Cell Biol 2014; 31:74-83. [PMID: 25259681 DOI: 10.1016/j.ceb.2014.09.003] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/08/2014] [Accepted: 09/08/2014] [Indexed: 12/26/2022]
Abstract
The Hippo network is a major conserved growth suppressor pathway that participates in organ size control during development and prevents tumour formation during adult homeostasis. Recent evidence has implicated the actin cytoskeleton as a link between tissue architecture and Hippo signalling. In this review, we will consider the evidence and models proposed for the regulation of Hippo signalling by actin dynamics and structure. We cover aspects of signalling regulation by mechanotransduction, cytoskeletal tethering and the spatial reorganization of signalling components. We also examine the physiological and pathological contexts in which these mechanisms are relevant.
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Affiliation(s)
- Pedro Gaspar
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, Apartado 14, 2780-156 Oeiras, Portugal
| | - Nicolas Tapon
- Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
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89
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Zhang Y, Xia H, Ge X, Chen Q, Yuan D, Chen Q, Leng W, Chen L, Tang Q, Bi F. CD44 acts through RhoA to regulate YAP signaling. Cell Signal 2014; 26:2504-13. [DOI: 10.1016/j.cellsig.2014.07.031] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/13/2014] [Accepted: 07/28/2014] [Indexed: 01/08/2023]
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90
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Buchmann A, Alber M, Zartman JJ. Sizing it up: The mechanical feedback hypothesis of organ growth regulation. Semin Cell Dev Biol 2014; 35:73-81. [DOI: 10.1016/j.semcdb.2014.06.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 06/26/2014] [Indexed: 11/28/2022]
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91
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Kwon HJ, Waghmare I, Verghese S, Singh A, Singh A, Kango-Singh M. Drosophila C-terminal Src kinase regulates growth via the Hippo signaling pathway. Dev Biol 2014; 397:67-76. [PMID: 25446534 DOI: 10.1016/j.ydbio.2014.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 09/15/2014] [Accepted: 10/14/2014] [Indexed: 12/11/2022]
Abstract
The Hippo signaling pathway is involved in regulating tissue size by inhibiting cell proliferation and promoting apoptosis. Aberrant Hippo pathway function is often detected in human cancers and correlates with poor prognosis. The Drosophila C-terminal Src kinase (d-Csk) is a genetic modifier of warts (wts), a tumor-suppressor gene in the Hippo pathway, and interacts with the Src oncogene. Reduction in d-Csk expression and the consequent activation of Src are frequently seen in several cancers including hepatocellular and colorectal tumors. Previous studies show that d-Csk regulates cell proliferation and tissue size during development. Given the similarity in the loss-of-function phenotypes of d-Csk and wts, we have investigated the interactions of d-Csk with the Hippo pathway. Here we present multiple lines of evidence suggesting that d-Csk regulates growth via the Hippo signaling pathway. We show that loss of dCsk caused increased Yki activity, and our genetic epistasis places dCsk downstream of Dachs. Furthermore, dCsk requires Yki for its growth regulatory functions, suggesting that dCsk is another upstream member of the network of genes that interact to regulate Wts and its effector Yki in the Hippo signaling pathway.
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Affiliation(s)
- Hailey J Kwon
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | | | - Shilpi Verghese
- Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Aditi Singh
- Centerville High School, Centerville, OH 45459, USA
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA; Center for Tissue Regeneration and Engineering at Dayton, Dayton, OH 45469, USA; Premedical Programs, University of Dayton, Dayton, OH 45469, USA
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, OH 45469, USA; Center for Tissue Regeneration and Engineering at Dayton, Dayton, OH 45469, USA; Premedical Programs, University of Dayton, Dayton, OH 45469, USA.
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92
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Cytoskeletal tension inhibits Hippo signaling through an Ajuba-Warts complex. Cell 2014; 158:143-156. [PMID: 24995985 DOI: 10.1016/j.cell.2014.05.035] [Citation(s) in RCA: 261] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 02/18/2014] [Accepted: 05/08/2014] [Indexed: 11/21/2022]
Abstract
Mechanical forces have been proposed to modulate organ growth, but a molecular mechanism that links them to growth regulation in vivo has been lacking. We report that increasing tension within the cytoskeleton increases Drosophila wing growth, whereas decreasing cytoskeletal tension decreases wing growth. These changes in growth can be accounted for by changes in the activity of Yorkie, a transcription factor regulated by the Hippo pathway. The influence of myosin activity on Yorkie depends genetically on the Ajuba LIM protein Jub, a negative regulator of Warts within the Hippo pathway. We further show that Jub associates with α-catenin and that its localization to adherens junctions and association with α-catenin are promoted by cytoskeletal tension. Jub recruits Warts to junctions in a tension-dependent manner. Our observations delineate a mechanism that links cytoskeletal tension to regulation of Hippo pathway activity, providing a molecular understanding of how mechanical forces can modulate organ growth.
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93
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Huang Y, McNeil GP, Jackson FR. Translational regulation of the DOUBLETIME/CKIδ/ε kinase by LARK contributes to circadian period modulation. PLoS Genet 2014; 10:e1004536. [PMID: 25211129 PMCID: PMC4161311 DOI: 10.1371/journal.pgen.1004536] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 06/12/2014] [Indexed: 12/02/2022] Open
Abstract
The Drosophila homolog of Casein Kinase I δ/ε, DOUBLETIME (DBT), is required for Wnt, Hedgehog, Fat and Hippo signaling as well as circadian clock function. Extensive studies have established a critical role of DBT in circadian period determination. However, how DBT expression is regulated remains largely unexplored. In this study, we show that translation of dbt transcripts are directly regulated by a rhythmic RNA-binding protein (RBP) called LARK (known as RBM4 in mammals). LARK promotes translation of specific alternative dbt transcripts in clock cells, in particular the dbt-RC transcript. Translation of dbt-RC exhibits circadian changes under free-running conditions, indicative of clock regulation. Translation of a newly identified transcript, dbt-RE, is induced by light in a LARK-dependent manner and oscillates under light/dark conditions. Altered LARK abundance affects circadian period length, and this phenotype can be modified by different dbt alleles. Increased LARK delays nuclear degradation of the PERIOD (PER) clock protein at the beginning of subjective day, consistent with the known role of DBT in PER dynamics. Taken together, these data support the idea that LARK influences circadian period and perhaps responses of the clock to light via the regulated translation of DBT. Our study is the first to investigate translational control of the DBT kinase, revealing its regulation by LARK and a novel role of this RBP in Drosophila circadian period modulation. The CKI family of serine/threonine kinase regulates diverse cellular processes, through binding to and phosphorylation of a variety of protein substrates. In mammals, mutations in two members of the family, CKIε and CKIδ were found to affect circadian period length, causing phenotypes such as altered circadian period in rodents and the Familial Advanced Sleep Phase Syndrome (FASPS) in human. The Drosophila CKI δ/ε homolog DOUBLETIME (DBT) is known to have important roles in development and circadian clock function. Despite extensive studies of DBT function, little is known about how its expression is regulated. In a previous genome-wide study, we identified dbt mRNAs as potential targets of the LARK RBP. Here we describe a detailed study of the regulation of DBT expression by LARK. We found that LARK binds to and regulates translation of dbt mRNA, promoting expression of a smaller isoform; we suggest this regulatory mechanism contributes to circadian period determination. In addition, we have identified a dbt mRNA that exhibits light-induced changes in translational status, in a LARK-dependent manner. Our study is the first to analyze the translational regulation of DBT, setting the stage for similar studies in other contexts and model systems.
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Affiliation(s)
- Yanmei Huang
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Gerard P McNeil
- Department of Biology, York College, Jamaica, New York, New York, United States of America
| | - F Rob Jackson
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
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94
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Bosch JA, Sumabat TM, Hafezi Y, Pellock BJ, Gandhi KD, Hariharan IK. The Drosophila F-box protein Fbxl7 binds to the protocadherin fat and regulates Dachs localization and Hippo signaling. eLife 2014; 3:e03383. [PMID: 25107277 PMCID: PMC4144329 DOI: 10.7554/elife.03383] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Drosophila protocadherin Fat (Ft) regulates growth, planar cell polarity (PCP) and proximodistal patterning. A key downstream component of Ft signaling is the atypical myosin Dachs (D). Multiple regions of the intracellular domain of Ft have been implicated in regulating growth and PCP but how Ft regulates D is not known. Mutations in Fbxl7, which encodes an F-box protein, result in tissue overgrowth and abnormalities in proximodistal patterning that phenocopy deleting a specific portion of the intracellular domain (ICD) of Ft that regulates both growth and PCP. Fbxl7 binds to this same portion of the Ft ICD, co-localizes with Ft to the proximal edge of cells and regulates the levels and asymmetry of D at the apical membrane. Fbxl7 can also regulate the trafficking of proteins between the apical membrane and intracellular vesicles. Thus Fbxl7 functions in a subset of pathways downstream of Ft and links Ft to D localization. DOI:http://dx.doi.org/10.7554/eLife.03383.001 Multi-cellular organisms are made up of cells that are organized into tissues and organs that reach a predictable size and shape at the end of their development. To do this, cells must be able to sense their position and orientation within the body and know when to stop growing. Epithelial cells—which make up the outer surface of an animal's body and line the cavities of its internal organs—connect to each other to form flat sheets. These sheets of cells contain structures that are oriented along the plane of the sheet. However, how this so-called ‘planar cell polarity’ coordinates with cell growth in order to build complex tissues and organs remains to be discovered. A protein called Fat is a major player in both planar cell polarity and the Hippo signaling pathway, which controls cell growth. As such, the Fat protein appears to be crucial for controlling the size and shape of organs. Mutations in the Fat protein cause massive tissue overgrowth, prevent planar cell polarity being established correctly, and stop the legs and wings of fruit flies developing normally. The Fat protein also plays a role in distributing another protein called Dachs—which is also part of the Hippo signaling pathway. In epithelial cells of the developing wing, Dachs is mostly located on the side of the cell that is closest to the tip of the developing wing (the so-called ‘distal surface’). How Fat and Dachs work together is not understood, but it is known that they do not bind to each other directly. Now, Bosch et al. show that in the fruit fly Drosophila, the Fat protein binds to another protein called Fbxl7. Flies that cannot produce working Fbxl7 have defects in some aspects of planar cell polarity and a modest increase in tissue growth. Fbxl7 seems to account for part, but not all, of the ability of Fat to restrict tissue growth. Furthermore, a lack of the Fbxl7 protein results in a spreading of Dachs protein across the apical surface—which faces out of the epithelial sheet—of epithelial cells. On the other hand, if Fbxl7 is over-expressed, Dachs is driven to the interior of each cell. Hence, a normal level of Fbxl7 protein restricts the Dachs protein to the correct parts of the cell surface. Together, the findings of Bosch et al. show that the Fbxl7 protein is a key link between the Fat and Dachs proteins. These results also provide an understanding of how growth and planar cell polarity—two processes that are essential for normal development of all multi-cellular organisms—are coordinated. DOI:http://dx.doi.org/10.7554/eLife.03383.002
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Affiliation(s)
- Justin A Bosch
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Taryn M Sumabat
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Yassi Hafezi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Brett J Pellock
- Department of Biology, Providence College, Providence, United States
| | - Kevin D Gandhi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Iswar K Hariharan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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95
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Codelia VA, Sun G, Irvine KD. Regulation of YAP by mechanical strain through Jnk and Hippo signaling. Curr Biol 2014; 24:2012-7. [PMID: 25127217 PMCID: PMC4160395 DOI: 10.1016/j.cub.2014.07.034] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 06/04/2014] [Accepted: 07/14/2014] [Indexed: 12/31/2022]
Abstract
Mechanical forces affect all the tissues of our bodies. Experiments conducted mainly on cultured cells have established that altering these forces influences cell behaviors, including migration, differentiation, apoptosis, and proliferation [1, 2]. The transcriptional coactivator YAP has been identified as a nuclear relay of mechanical signals, but the molecular mechanisms that lead to YAP activation were not identified [3]. YAP is the main transcriptional effector of the Hippo signaling pathway, a major growth regulatory pathway within metazoa [4], but at least in some instances, the influence of mechanical strain on YAP was reported to be independent of Hippo signaling [5, 6]. Here, we identify a molecular pathway that can promote the proliferation of cultured mammary epithelial cells in response to cyclic or static stretch. These mechanical stimuli are associated with increased activity of the transcriptional coactivator YAP, which is due at least in part to inhibition of Hippo pathway activity. Much of this influence on Hippo signaling can be accounted for by the activation of c-Jun N-terminal kinase (JNK) activity by mechanical strain and subsequent inhibition of Hippo signaling by JNK. LATS1 is a key negative regulator of YAP within the Hippo pathway, and we further show that cyclic stretch is associated with a JNK-dependent increase in binding of a LATS inhibitor, LIMD1, to the LATS1 kinase and that reduction of LIMD1 expression suppresses the activation of YAP by cyclic stretch. Together, these observations establish a pathway for mechanical regulation of cell proliferation via JNK-mediated inhibition of Hippo signaling.
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Affiliation(s)
- Veronica A Codelia
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Gongping Sun
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Kenneth D Irvine
- Howard Hughes Medical Institute, Waksman Institute, and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
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96
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Abstract
The Hippo signaling pathway, consisting of a highly conserved kinase cascade (MST and Lats) and downstream transcription coactivators (YAP and TAZ), plays a key role in tissue homeostasis and organ size control by regulating tissue-specific stem cells. Moreover, this pathway plays a prominent role in tissue repair and regeneration. Dysregulation of the Hippo pathway is associated with cancer development. Recent studies have revealed a complex network of upstream inputs, including cell density, mechanical sensation, and G-protein-coupled receptor (GPCR) signaling, that modulate Hippo pathway activity. This review focuses on the role of the Hippo pathway in stem cell biology and its potential implications in tissue homeostasis and cancer.
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Affiliation(s)
- Jung-Soon Mo
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego La Jolla, CA, USA
| | - Hyun Woo Park
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego La Jolla, CA, USA
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego La Jolla, CA, USA
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97
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Huang J, Kalderon D. Coupling of Hedgehog and Hippo pathways promotes stem cell maintenance by stimulating proliferation. ACTA ACUST UNITED AC 2014; 205:325-38. [PMID: 24798736 PMCID: PMC4018789 DOI: 10.1083/jcb.201309141] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It is essential to define the mechanisms by which external signals regulate adult stem cell numbers, stem cell maintenance, and stem cell proliferation to guide regenerative stem cell therapies and to understand better how cancers originate in stem cells. In this paper, we show that Hedgehog (Hh) signaling in Drosophila melanogaster ovarian follicle stem cells (FSCs) induces the activity of Yorkie (Yki), the transcriptional coactivator of the Hippo pathway, by inducing yki transcription. Moreover, both Hh signaling and Yki positively regulate the rate of FSC proliferation, both are essential for FSC maintenance, and both promote increased FSC longevity and FSC duplication when in excess. We also found that responses to activated Yki depend on Cyclin E induction while responses to excess Hh signaling depend on Yki induction, and excess Yki can compensate for defective Hh signaling. These causal connections provide the most rigorous evidence to date that a niche signal can promote stem cell maintenance principally by stimulating stem cell proliferation.
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Affiliation(s)
- Jianhua Huang
- Department of Biological Sciences, Columbia University, New York, NY 10027
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98
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Abstract
Cancer was seen for a long time as a strictly cell-autonomous process in which oncogenes and tumor-suppressor mutations drive clonal cell expansions. Research in the past decade, however, paints a more integrative picture of communication and interplay between neighboring cells in tissues. It is increasingly clear as well that tumors, far from being homogenous lumps of cells, consist of different cell types that function together as complex tissue-level communities. The repertoire of interactive cell behaviors and the quantity of cellular players involved call for a social cell biology that investigates these interactions. Research into this social cell biology is critical for understanding development of normal and tumoral tissues. Such complex social cell biology interactions can be parsed in Drosophila. Techniques in Drosophila for analysis of gene function and clonal behavior allow us to generate tumors and dissect their complex interactive biology with cellular resolution. Here, we review recent Drosophila research aimed at understanding tissue-level biology and social cell interactions in tumors, highlighting the principles these studies reveal.
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99
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Cao Y, White HD, Li XD. Drosophila myosin-XX functions as an actin-binding protein to facilitate the interaction between Zyx102 and actin. Biochemistry 2014; 53:350-60. [PMID: 24393048 DOI: 10.1021/bi401236c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The class XX myosin is a member of the diverse myosin superfamily and exists in insects and several lower invertebrates. DmMyo20, the class XX myosin in Drosophila, is encoded by dachs, which functions as a crucial downstream component of the Fat signaling pathway, influencing growth, affinity, and gene expression during development. Sequence analysis shows that DmMyo20 contains a unique N-terminal extension, the motor domain, followed by one IQ motif, and a C-terminal tail. To investigate the biochemical properties of DmMyo20, we expressed several DmMyo20 truncated constructs containing the motor domain in the baculovirus/Sf9 system. We found that the motor domain of DmMyo20 had neither ATPase activity nor the ability to bind to ATP, suggesting that DmMyo20 does not function as a molecular motor. We found that the motor domain of DmMyo20 could specifically bind to actin filaments in an ATP-independent manner and enhance the interaction between actin filaments and Zyx102, a downstream component of DmMyo20 in the Fat signaling pathway. These results suggest that DmMyo20 functions as a scaffold protein, but not as a molecular motor, in a signaling pathway controlling cell differentiation.
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Affiliation(s)
- Yang Cao
- Group of Cell Motility and Muscle Contraction, National Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences , Beijing 100101, China
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100
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Johnson R, Halder G. The two faces of Hippo: targeting the Hippo pathway for regenerative medicine and cancer treatment. Nat Rev Drug Discov 2013; 13:63-79. [PMID: 24336504 DOI: 10.1038/nrd4161] [Citation(s) in RCA: 693] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Hippo signalling pathway is an emerging growth control and tumour suppressor pathway that regulates cell proliferation and stem cell functions. Defects in Hippo signalling and hyperactivation of its downstream effectors Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) contribute to the development of cancer, which suggests that pharmacological inhibition of YAP and TAZ activity may be an effective anticancer strategy. Conversely, YAP and TAZ can also have beneficial roles in stimulating tissue repair and regeneration following injury, so their activation may be therapeutically useful in these contexts. A complex network of intracellular and extracellular signalling pathways that modulate YAP and TAZ activities have recently been identified. Here, we review the regulation of the Hippo signalling pathway, its functions in normal homeostasis and disease, and recent progress in the identification of small-molecule pathway modulators.
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Affiliation(s)
- Randy Johnson
- 1] Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. [2] Genes and Development Program, and Cancer Biology Program, Graduate School for Biological Sciences, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. [3] Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Georg Halder
- VIB Center for the Biology of Disease, KU Leuven Center for Human Genetics, University of Leuven 3000, Belgium
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