scholarly journals STK25 suppresses Hippo signaling by regulating SAV1-STRIPAK antagonism

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Sung Jun Bae ◽  
Lisheng Ni ◽  
Xuelian Luo
Keyword(s):  
Hippo Pathway ◽  
Human Cells ◽  
Tissue Homeostasis ◽  
Organ Size ◽  
Scaffolding Protein ◽  
Hippo Signaling ◽  
Mutual Antagonism ◽  
Kinase Cascade ◽  
The Hippo Pathway

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

scholarly journals The Hippo-Yes Association Protein Pathway in Liver Cancer

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lu Jie ◽  
Wang Fan ◽  
Dai Weiqi ◽  
Zhou Yingqun ◽  
Xu Ling ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Hippo Pathway ◽  
Tumor Development ◽  
Size Control ◽  
Organ Size ◽  
Regulation Of Transcription ◽  
Hippo Signaling ◽  
Evolutionary Changes ◽  
Kinase Cascade ◽  
The Hippo Pathway

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the third leading cause of cancer mortality. Despite continuing development of new therapies, prognosis for patients with HCC remains extremely poor. In recent years, control of organ size becomes a hot topic in HCC development. The Hippo signaling pathway has been delineated and shown to be critical in controlling organ size in both Drosophila and mammals. The Hippo kinase cascade, a singling pathway that antagonizes the transcriptional coactivator Yes-associated protein (YAP), plays an important role in animal organ size control by regulating cell proliferation and apoptosis rates. During HCC development, this pathway is likely inactivated in tumor initiated cells that escape suppressive constrain exerted by the surrounding normal tissue, thus allowing clonal expansion and tumor development. We have reviewed evolutionary changes in YAP as well as other components of the Hippo pathway and described the relationships between YAP genes and HCC. We also discuss regulation of transcription factors that are up- and downstream of YAP in liver cancer development.

scholarly journals The Hippo Pathway: Immunity and Cancer

Cancers ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 94 ◽  
Author(s):  
Zaid Taha ◽  
Helena Janse van Rensburg ◽  
Xiaolong Yang
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Mammalian Cells ◽  
Immune Cell ◽  
Hippo Pathway ◽  
Tissue Homeostasis ◽  
Hippo Signaling ◽  
Core Components ◽  
The Hippo Pathway ◽  
Future Work

Since its discovery, the Hippo pathway has emerged as a central signaling network in mammalian cells. Canonical signaling through the Hippo pathway core components (MST1/2, LATS1/2, YAP and TAZ) is important for development and tissue homeostasis while aberrant signaling through the Hippo pathway has been implicated in multiple pathologies, including cancer. Recent studies have uncovered new roles for the Hippo pathway in immunology. In this review, we summarize the mechanisms by which Hippo signaling in pathogen-infected or neoplastic cells affects the activities of immune cells that respond to these threats. We further discuss how Hippo signaling functions as part of an immune response. Finally, we review how immune cell-intrinsic Hippo signaling modulates the development/function of leukocytes and propose directions for future work.

Drosophila Hcf regulates the Hippo signaling pathway via association with the histone H3K4 methyltransferase Trr

2019 ◽  
Vol 476 (4) ◽  
pp. 759-768 ◽  
Author(s):  
Zi Nan ◽  
Weiwei Yang ◽  
Jialan Lyu ◽  
Fang Wang ◽  
Qiannan Deng ◽  
...  
Keyword(s):  
Host Cell ◽  
Signaling Pathway ◽  
Hippo Pathway ◽  
Organ Size ◽  
Fundamental Aspect ◽  
Hippo Signaling ◽  
Hippo Signaling Pathway ◽  
Host Cell Factor ◽  
Histone H3k4 ◽  
The Hippo Pathway

Abstract Control of organ size is a fundamental aspect in biology and plays important roles in development. The Hippo pathway is a conserved signaling cascade that controls tissue and organ size through the regulation of cell proliferation and apoptosis. Here, we report on the roles of Hcf (host cell factor), the Drosophila homolog of Host cell factor 1, in regulating the Hippo signaling pathway. Loss-of-Hcf function causes tissue undergrowth and the down-regulation of Hippo target gene expression. Genetic analysis reveals that Hcf is required for Hippo pathway-mediated overgrowth. Mechanistically, we show that Hcf associates with the histone H3 lysine-4 methyltransferase Trithorax-related (Trr) to maintain H3K4 mono- and trimethylation. Thus, we conclude that Hcf positively regulates Hippo pathway activity through forming a complex with Trr and controlling H3K4 methylation.

scholarly journals Hippo signaling in the kidney: the good and the bad

2016 ◽  
Vol 311 (2) ◽  
pp. F241-F248 ◽  
Author(s):  
Jenny S. Wong ◽  
Kristin Meliambro ◽  
Justina Ray ◽  
Kirk N. Campbell
Keyword(s):  
Embryonic Development ◽  
Current Knowledge ◽  
Hippo Pathway ◽  
Hippo Signaling ◽  
Filtration Barrier ◽  
Signaling Axis ◽  
Kinase Cascade ◽  
Barrier Regulation ◽  
Renal Tubular ◽  
The Hippo Pathway

The Hippo signaling pathway is an evolutionarily conserved kinase cascade, playing multiple roles in embryonic development that controls organ size, cell proliferation, and apoptosis. At the center of this network lie the Hippo kinase target and downstream pathway effector Yes-associated protein (YAP) and its paralog TAZ. In its phosphorylated form, cytoplasmic YAP is sequestered in an inactive state. When it is dephosphorylated, YAP, a potent oncogene, is activated and relocates to the nucleus to interact with a number of transcription factors and signaling regulators that promote cell growth, differentiation, and survival. The identification of YAP activation in human cancers has made it an attractive target for chemotherapeutic drug development. Little is known to date about the function of the Hippo pathway in the kidney, but that is rapidly changing. Recent studies have shed light on the role of Hippo-YAP signaling in glomerular and lower urinary tract embryonic development, maintenance of podocyte homeostasis, the integrity of the glomerular filtration barrier, regulation of renal tubular cyst growth, renal epithelial injury in diabetes, and renal fibrogenesis. This review summarizes the current knowledge of the Hippo-YAP signaling axis in the kidney under normal and disease conditions.

scholarly journals Hippo and rassf1a Pathways: A Growing Affair

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Francesca Fausti ◽  
Silvia Di Agostino ◽  
Andrea Sacconi ◽  
Sabrina Strano ◽  
Giovanni Blandino
Keyword(s):  
Developmental Biology ◽  
Tissue Regeneration ◽  
Target Genes ◽  
Hippo Pathway ◽  
Hippo Signaling ◽  
Transcriptional Coactivator ◽  
Pathway Activity ◽  
Kinase Cascade ◽  
The Hippo Pathway ◽  
The Impact

First discovered in Drosophila, the Hippo pathway regulates the size and shape of organ development. Its discovery and study have helped to address longstanding questions in developmental biology. Central to this pathway is a kinase cascade leading from the tumor suppressor Hippo (Mst1 and Mst2 in mammals) to the Yki protein (YAP and TAZ in mammals), a transcriptional coactivator of target genes involved in cell proliferation, survival, and apoptosis. A dysfunction of the Hippo pathway activity is frequently detected in human cancers. Recent studies have highlighted that the Hippo pathway may play an important role in tissue homoeostasis through the regulation of stem cells, cell differentiation, and tissue regeneration. Recently, the impact of RASSF proteins on Hippo signaling potentiating its proapoptotic activity has been addressed, thus, providing further evidence for Hippo's key role in mammalian tumorigenesis as well as other important diseases.

scholarly journals Mutations and Copy Number Abnormalities of Hippo Pathway Components in Human Cancers

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhengjin He ◽  
Ruihan Li ◽  
Hai Jiang
Keyword(s):  
Cell Proliferation ◽  
Cancer Cells ◽  
Copy Number ◽  
Human Cancer ◽  
Hippo Pathway ◽  
Copy Number Variations ◽  
Tissue Homeostasis ◽  
Hippo Signaling ◽  
Core Components ◽  
The Hippo Pathway

The Hippo pathway is highly conserved from Drosophila to mammals. As a key regulator of cell proliferation, the Hippo pathway controls tissue homeostasis and has a major impact on tumorigenesis. The originally defined core components of the Hippo pathway in mammals include STK3/4, LATS1/2, YAP1/TAZ, TEAD, VGLL4, and NF2. However, for most of these genes, mutations and copy number variations are relatively uncommon in human cancer. Several other recently identified upstream and downstream regulators of Hippo signaling, including FAT1, SHANK2, Gq/11, and SWI/SNF complex, are more commonly dysregulated in human cancer at the genomic level. This review will discuss major genomic events in human cancer that enable cancer cells to escape the tumor-suppressive effects of Hippo signaling.

scholarly journals SAV1 promotes Hippo kinase activation through antagonizing the PP2A phosphatase STRIPAK

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Sung Jun Bae ◽  
Lisheng Ni ◽  
Adam Osinski ◽  
Diana R Tomchick ◽  
Chad A Brautigam ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Hippo Pathway ◽  
Tissue Growth ◽  
Activation Loop ◽  
Hippo Signaling ◽  
Ww Domains ◽  
Kinase Activation ◽  
Genetic Ablation ◽  
Kinase Cascade ◽  
The Hippo Pathway

The Hippo pathway controls tissue growth and homeostasis through a central MST-LATS kinase cascade. The scaffold protein SAV1 promotes the activation of this kinase cascade, but the molecular mechanisms remain unknown. Here, we discover SAV1-mediated inhibition of the PP2A complex STRIPAKSLMAP as a key mechanism of MST1/2 activation. SLMAP binding to autophosphorylated MST2 linker recruits STRIPAK and promotes PP2A-mediated dephosphorylation of MST2 at the activation loop. Our structural and biochemical studies reveal that SAV1 and MST2 heterodimerize through their SARAH domains. Two SAV1–MST2 heterodimers further dimerize through SAV1 WW domains to form a heterotetramer, in which MST2 undergoes trans-autophosphorylation. SAV1 directly binds to STRIPAK and inhibits its phosphatase activity, protecting MST2 activation-loop phosphorylation. Genetic ablation of SLMAP in human cells leads to spontaneous activation of the Hippo pathway and alleviates the need for SAV1 in Hippo signaling. Thus, SAV1 promotes Hippo activation through counteracting the STRIPAKSLMAP PP2A phosphatase complex.

scholarly journals Activation mechanisms of the Hippo kinase signaling cascade

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Sung Jun Bae ◽  
Xuelian Luo
Keyword(s):  
Hippo Pathway ◽  
Adaptor Proteins ◽  
Tissue Growth ◽  
Fine Tuning ◽  
Hippo Signaling ◽  
Kinase Activation ◽  
The Core ◽  
Activation Mechanisms ◽  
Kinase Cascade ◽  
The Hippo Pathway

First discovered two decades ago through genetic screens in Drosophila, the Hippo pathway has been shown to be conserved in metazoans and controls organ size and tissue homeostasis through regulating the balance between cell proliferation and apoptosis. Dysregulation of the Hippo pathway leads to aberrant tissue growth and tumorigenesis. Extensive studies in Drosophila and mammals have identified the core components of Hippo signaling, which form a central kinase cascade to ultimately control gene expression. Here, we review recent structural, biochemical, and cellular studies that have revealed intricate phosphorylation-dependent mechanisms in regulating the formation and activation of the core kinase complex in the Hippo pathway. These studies have established the dimerization-mediated activation of the Hippo kinase (mammalian Ste20-like 1 and 2 (MST1/2) in mammals), the dynamic scaffolding and allosteric roles of adaptor proteins in downstream kinase activation, and the importance of multisite linker autophosphorylation by Hippo and MST1/2 in fine-tuning the signaling strength and robustness of the Hippo pathway. We highlight the gaps in our knowledge in this field that will require further mechanistic studies.

scholarly journals Hippo Pathway in Regulating Drug Resistance of Glioblastoma

2021 ◽  
Vol 22 (24) ◽  
pp. 13431
Author(s):  
Giacomo Casati ◽  
Laura Giunti ◽  
Anna Lisa Iorio ◽  
Arianna Marturano ◽  
Luisa Galli ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Binding Motif ◽  
Hippo Signaling ◽  
Pathway Activation ◽  
Promising Target ◽  
Kinase Cascade ◽  
Tumor Immunosuppression ◽  
The Central Nervous System ◽  
Immunosuppressive Microenvironment ◽  
The Hippo Pathway

Glioblastoma (GBM) represents the most common and malignant tumor of the Central Nervous System (CNS), affecting both children and adults. GBM is one of the deadliest tumor types and it shows a strong multidrug resistance (MDR) and an immunosuppressive microenvironment which remain a great challenge to therapy. Due to the high recurrence of GBM after treatment, the understanding of the chemoresistance phenomenon and how to stimulate the antitumor immune response in this pathology is crucial. The deregulation of the Hippo pathway is involved in tumor genesis, chemoresistance and immunosuppressive nature of GBM. This pathway is an evolutionarily conserved signaling pathway with a kinase cascade core, which controls the translocation of YAP (Yes-Associated Protein)/TAZ (Transcriptional Co-activator with PDZ-binding Motif) into the nucleus, leading to regulation of organ size and growth. With this review, we want to highlight how chemoresistance and tumor immunosuppression work in GBM and how the Hippo pathway has a key role in them. We linger on the role of the Hippo pathway evaluating the effect of its de-regulation among different human cancers. Moreover, we consider how different pathways are cross-linked with the Hippo signaling in GBM genesis and the hypothetical mechanisms responsible for the Hippo pathway activation in GBM. Furthermore, we describe various drugs targeting the Hippo pathway. In conclusion, all the evidence described largely support a strong involvement of the Hippo pathway in gliomas progression, in the activation of chemoresistance mechanisms and in the development of an immunosuppressive microenvironment. Therefore, this pathway is a promising target for the treatment of high grade gliomas and in particular of GBM.

scholarly journals Spectrin regulates Hippo signaling by modulating cortical actomyosin activity

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Hua Deng ◽  
Wei Wang ◽  
Jianzhong Yu ◽  
Yonggang Zheng ◽  
Yun Qing ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Myosin Ii ◽  
Tissue Growth ◽  
Hippo Signaling ◽  
Upstream Regulator ◽  
Kinase Cascade ◽  
Cytoskeletal Tension ◽  
Living Tissues ◽  
The Hippo Pathway ◽  
Upstream Regulators

The Hippo pathway controls tissue growth through a core kinase cascade that impinges on the transcription of growth-regulatory genes. Understanding how this pathway is regulated in development remains a major challenge. Recent studies suggested that Hippo signaling can be modulated by cytoskeletal tension through a Rok-myosin II pathway. How cytoskeletal tension is regulated or its relationship to the other known upstream regulators of the Hippo pathway remains poorly defined. In this study, we identify spectrin, a contractile protein at the cytoskeleton-membrane interface, as an upstream regulator of the Hippo signaling pathway. We show that, in contrast to canonical upstream regulators such as Crumbs, Kibra, Expanded, and Merlin, spectrin regulates Hippo signaling in a distinct way by modulating cortical actomyosin activity through non-muscle myosin II. These results uncover an essential mediator of Hippo signaling by cytoskeleton tension, providing a new entry point to dissecting how mechanical signals regulate Hippo signaling in living tissues.

Sign in / Sign up

Export Citation Format

Share Document