scholarly journals Adhesion to fibronectin regulates Hippo signaling via the FAK–Src–PI3K pathway

2015 ◽  
Vol 210 (3) ◽  
pp. 503-515 ◽  
Author(s):  
Nam-Gyun Kim ◽  
Barry M. Gumbiner

The Hippo pathway is involved in the regulation of contact inhibition of proliferation and responses to various physical and chemical stimuli. Recently, several upstream negative regulators of Hippo signaling, including epidermal growth factor receptor ligands and lysophosphatidic acid, have been identified. We show that fibronectin adhesion stimulation of focal adhesion kinase (FAK)-Src signaling is another upstream negative regulator of the Hippo pathway. Inhibition of FAK or Src in MCF-10A cells plated at low cell density prevented the activation of Yes-associated protein (YAP) in a large tumor suppressor homologue (Lats)–dependent manner. Attachment of serum-starved MCF-10A cells to fibronectin, but not poly-d-lysine or laminin, induced YAP nuclear accumulation via the FAK–Src–phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K) signaling pathway. Attenuation of FAK, Src, PI3K, or PDK1 activity blocked YAP nuclear accumulation stimulated by adhesion to fibronectin. This negative regulation of the Hippo pathway by fibronectin adhesion signaling can, at least in part, explain the effects of cell spreading on YAP nuclear localization and represents a Lats-dependent component of the response to cell adhesion.

2011 ◽  
Vol 193 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Sandra Habbig ◽  
Malte P. Bartram ◽  
Roman U. Müller ◽  
Ricarda Schwarz ◽  
Nikolaos Andriopoulos ◽  
...  

The conserved Hippo signaling pathway regulates organ size in Drosophila melanogaster and mammals and has an essential role in tumor suppression and the control of cell proliferation. Recent studies identified activators of Hippo signaling, but antagonists of the pathway have remained largely elusive. In this paper, we show that NPHP4, a known cilia-associated protein that is mutated in the severe degenerative renal disease nephronophthisis, acts as a potent negative regulator of mammalian Hippo signaling. NPHP4 directly interacted with the kinase Lats1 and inhibited Lats1-mediated phosphorylation of the Yes-associated protein (YAP) and TAZ (transcriptional coactivator with PDZ-binding domain), leading to derepression of these protooncogenic transcriptional regulators. Moreover, NPHP4 induced release from 14-3-3 binding and nuclear translocation of YAP and TAZ, promoting TEA domain (TEAD)/TAZ/YAP-dependent transcriptional activity. Consistent with these data, knockdown of NPHP4 negatively affected cellular proliferation and TEAD/TAZ activity, essentially phenocopying loss of TAZ function. These data identify NPHP4 as a negative regulator of the Hippo pathway and suggest that NPHP4 regulates cell proliferation through its effects on Hippo signaling.


2021 ◽  
Vol 22 (4) ◽  
pp. 2016
Author(s):  
Giulia Stefania Tavanti ◽  
Chiara Verdelli ◽  
Annamaria Morotti ◽  
Paola Maroni ◽  
Vito Guarnieri ◽  
...  

The Hippo pathway is involved in human tumorigenesis and tissue repair. Here, we investigated the Hippo coactivator Yes-associated protein 1 (YAP1) and the kinase large tumor suppressor 1/2 (LATS1/2) in tumors of the parathyroid glands, which are almost invariably associated with primary hyperparathyroidism. Compared with normal parathyroid glands, parathyroid adenomas (PAds) and carcinomas show variably but reduced nuclear YAP1 expression. The kinase LATS1/2, which phosphorylates YAP1 thus promoting its degradation, was also variably reduced in PAds. Further, YAP1 silencing reduces the expression of the key parathyroid oncosuppressor multiple endocrine neoplasia type 1(MEN1), while MEN1 silencing increases YAP1 expression. Treatment of patient-derived PAds-primary cell cultures and Human embryonic kidney 293A (HEK293A) cells expressing the calcium-sensing receptor (CASR) with the CASR agonist R568 induces YAP1 nuclear accumulation. This effect was prevented by the incubation of the cells with RhoA/Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitors Y27632 and H1152. Lastly, CASR activation increased the expression of the YAP1 gene targets CYR61, CTGF, and WNT5A, and this effect was blunted by YAP1 silencing. Concluding, here we provide preliminary evidence of the involvement of the Hippo pathway in human tumor parathyroid cells and of the existence of a CASR-ROCK-YAP1 axis. We propose a tumor suppressor role for YAP1 and LATS1/2 in parathyroid tumors.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anke Hermann ◽  
Guangming Wu ◽  
Pavel I. Nedvetsky ◽  
Viktoria C. Brücher ◽  
Charlotte Egbring ◽  
...  

AbstractThe WW-and-C2-domain-containing (WWC) protein family is involved in the regulation of cell differentiation, cell proliferation, and organ growth control. As upstream components of the Hippo signaling pathway, WWC proteins activate the Large tumor suppressor (LATS) kinase that in turn phosphorylates Yes-associated protein (YAP) and its paralog Transcriptional coactivator-with-PDZ-binding motif (TAZ) preventing their nuclear import and transcriptional activity. Inhibition of WWC expression leads to downregulation of the Hippo pathway, increased expression of YAP/TAZ target genes and enhanced organ growth. In mice, a ubiquitous Wwc1 knockout (KO) induces a mild neurological phenotype with no impact on embryogenesis or organ growth. In contrast, we could show here that ubiquitous deletion of Wwc2 in mice leads to early embryonic lethality. Wwc2 KO embryos display growth retardation, a disturbed placenta development, impaired vascularization, and finally embryonic death. A whole-transcriptome analysis of embryos lacking Wwc2 revealed a massive deregulation of gene expression with impact on cell fate determination, cell metabolism, and angiogenesis. Consequently, a perinatal, endothelial-specific Wwc2 KO in mice led to disturbed vessel formation and vascular hypersprouting in the retina. In summary, our data elucidate a novel role for Wwc2 as a key regulator in early embryonic development and sprouting angiogenesis in mice.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Pengfei Guo ◽  
Chang-Hyun Lee ◽  
Huiyan Lei ◽  
Yonggang Zheng ◽  
Katiuska Daniela Pulgar Prieto ◽  
...  

The Hippo tumor suppressor pathway regulates tissue growth in Drosophila by restricting the activity of the transcriptional coactivator Yorkie (Yki), which normally complexes with the TEF/TEAD family DNA-binding transcription factor Scalloped (Sd) to drive the expression of growth-promoting genes. Given its pivotal role as a central hub in mediating the transcriptional output of Hippo signaling, there is great interest in understanding the molecular regulation of the Sd-Yki complex. In this study, we identify Nerfin-1 as a transcriptional repressor that antagonizes the activity of the Sd-Yki complex by binding to the TEA DNA-binding domain of Sd. Consistent with its biochemical function, ectopic expression of Nerfin-1 results in tissue undergrowth in an Sd-dependent manner. Conversely, loss of Nerfin-1 enhances the ability of winner cells to eliminate loser cells in multiple scenarios of cell competition. We further show that INSM1, the mammalian ortholog of Nerfin-1, plays a conserved role in repressing the activity of the TEAD-YAP complex. These findings reveal a novel regulatory mode converging on the transcriptional output of the Hippo pathway that may be exploited for modulating the YAP oncoprotein in cancer and regenerative medicine.


2019 ◽  
Vol 116 (20) ◽  
pp. 9877-9882 ◽  
Author(s):  
Nam-Gyun Kim ◽  
Barry M. Gumbiner

The Hippo pathway is involved in regulating contact inhibition of proliferation and organ size control and responds to various physical and biochemical stimuli. It is a kinase cascade that negatively regulates the activity of cotranscription factors YAP and TAZ, which interact with DNA binding transcription factors including TEAD and activate the expression of target genes. In this study, we show that the palmitoylation of TEAD, which controls the activity and stability of TEAD proteins, is actively regulated by cell density independent of Lats, the key kinase of the Hippo pathway. The expression of fatty acid synthase and acetyl-CoA carboxylase involved in de novo biosynthesis of palmitate is reduced by cell density in an Nf2/Merlin-dependent manner. Depalmitoylation of TEAD is mediated by depalmitoylases including APT2 and ABHD17A. Palmitoylation-deficient TEAD4 mutant is unstable and degraded by proteasome through the activity of the E3 ubiquitin ligase CHIP. These findings show that TEAD activity is tightly controlled through the regulation of palmitoylation and stability via the orchestration of FASN, depalmitoylases, and E3 ubiquitin ligase in response to cell contact.


2017 ◽  
Vol 114 (18) ◽  
pp. 4691-4696 ◽  
Author(s):  
Youngeun Kim ◽  
Wantae Kim ◽  
Yonghee Song ◽  
Jeong-Rae Kim ◽  
Kyungjoo Cho ◽  
...  

Hippo signaling controls the expression of genes regulating cell proliferation and survival and organ size. The regulation of core components in the Hippo pathway by phosphorylation has been extensively investigated, but the roles of ubiquitination−deubiquitination processes are largely unknown. To identify deubiquitinase(s) that regulates Hippo signaling, we performed unbiased siRNA screening and found that YOD1 controls biological responses mediated by YAP/TAZ. Mechanistically, YOD1 deubiquitinates ITCH, an E3 ligase of LATS, and enhances the stability of ITCH, which leads to reduced levels of LATS and a subsequent increase in the YAP/TAZ level. Furthermore, we show that the miR-21-mediated regulation of YOD1 is responsible for the cell-density-dependent changes in YAP/TAZ levels. Using a transgenic mouse model, we demonstrate that the inducible expression of YOD1 enhances the proliferation of hepatocytes and leads to hepatomegaly in a YAP/TAZ-activity-dependent manner. Moreover, we find a strong correlation between YOD1 and YAP expression in liver cancer patients. Overall, our data strongly suggest that YOD1 is a regulator of the Hippo pathway and would be a therapeutic target to treat liver cancer.


2021 ◽  
Author(s):  
Jun Zhou ◽  
Zhen Yang ◽  
Cuishun Yang ◽  
Hua Lin ◽  
Wanqiong Yuan

Abstract Background: Gastrointestinal stromal tumor (GIST) is one of most common mesenchymal neoplasms occurring in different areas of the gastrointestinal tract. GISTs with cutaneous metastasis is very rare and its rarity cutaneous GISTs have not been well characterized. Focal segmental glomerulosclerosis (FSGS) is also rare among paraneoplastic nephritic syndromes (PNS).Case presentation: In this case report, we described a 64-year-old patient with cutaneous metastasis GIST accompanied by nephrotic syndrome as PNS, in whom symptomatic treatment was ineffective, but clinical remission was achieved after surgery. Moreover, the patient has a missense mutation of NPHP4. NPHP4 served as a negative regulator of the Hippo pathway. Hippo signaling pathway is involved in the development and progression of FSGS. NPHP4 is also indeed a driving force for proliferation in tumor cells. Therefore, the mutation of NPHP4 in this patient could explain the occurrence of GIST and FSGS and this was therefore not a random association.Conclusions: This is the first reported case of a GIST with cutaneous metastasis accompanied by nephrotic syndrome as PNS.


Author(s):  
Piera Tocci ◽  
Giovanni Blandino ◽  
Anna Bagnato

AbstractThe rational making the G protein-coupled receptors (GPCR) the centerpiece of targeted therapies is fueled by the awareness that GPCR-initiated signaling acts as pivotal driver of the early stages of progression in a broad landscape of human malignancies. The endothelin-1 (ET-1) receptors (ET-1R), known as ETA receptor (ETAR) and ETB receptor (ETBR) that belong to the GPCR superfamily, affect both cancer initiation and progression in a variety of cancer types. By the cross-talking with multiple signaling pathways mainly through the scaffold protein β-arrestin1 (β-arr1), ET-1R axis cooperates with an array of molecular determinants, including transcription factors and co-factors, strongly affecting tumor cell fate and behavior. In this scenario, recent findings shed light on the interplay between ET-1 and the Hippo pathway. In ETAR highly expressing tumors ET-1 axis induces the de-phosphorylation and nuclear accumulation of the Hippo pathway downstream effectors, the paralogous transcriptional cofactors Yes-associated protein (YAP) and Transcriptional coactivator with PDZ-binding motif (TAZ). Recent evidence have discovered that ET-1R/β-arr1 axis instigates a transcriptional interplay involving YAP and mutant p53 proteins, which share a common gene signature and cooperate in a oncogenic signaling network. Mechanistically, YAP and mutp53 are enrolled in nuclear complexes that turn on a highly selective YAP/mutp53-dependent transcriptional response. Notably, ET-1R blockade by the FDA approved dual ET-1 receptor antagonist macitentan interferes with ET-1R/YAP/mutp53 signaling interplay, through the simultaneous suppression of YAP and mutp53 functions, hampering metastasis and therapy resistance. Based on these evidences, we aim to review the recent findings linking the GPCR signaling, as for ET-1R, to YAP/TAZ signaling, underlining the clinical relevance of the blockade of such signaling network in the tumor and microenvironmental contexts. In particular, we debate the clinical implications regarding the use of dual ET-1R antagonists to blunt gain of function activity of mutant p53 proteins and thereby considering them as a potential therapeutic option for mutant p53 cancers. The identification of ET-1R/β-arr1-intertwined and bi-directional signaling pathways as targetable vulnerabilities, may open new therapeutic approaches able to disable the ET-1R-orchestrated YAP/mutp53 signaling network in both tumor and stromal cells and concurrently sensitizes to high-efficacy combined therapeutics.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 729
Author(s):  
Clara Reglero ◽  
Belén Ortiz del Castillo ◽  
Verónica Rivas ◽  
Federico Mayor ◽  
Petronila Penela

The timing of centrosome separation and the distance moved apart influence the formation of the bipolar spindle, affecting chromosome stability. Epidermal growth factor receptor (EGFR) signaling induces early centrosome separation through downstream G protein-coupled receptor kinase GRK2, which phosphorylates the Hippo pathway component MST2 (Mammalian STE20-like protein kinase 2), in turn allowing NIMA kinase Nek2A activation for centrosomal linker disassembly. However, the mechanisms that counterbalance centrosome disjunction and separation remain poorly understood. We unveil that timely degradation of GRK2 by the E3 ligase Mdm2 limits centrosome separation in the G2. Both knockout expression and catalytic inhibition of Mdm2 result in GRK2 accumulation and enhanced centrosome separation before mitosis onset. Phosphorylation of GRK2 on residue S670 enables a complex pattern of non-K48-linked polyubiquitin chains assembled by Mdm2, which correlate with kinase protein degradation. Remarkably, GRK2-S670A protein fails to phosphorylate MST2 despite overcoming Mdm2-dependent degradation, which results in defective centrosome separation, shorter spindles, and abnormal chromosome congression. Conversely, extra levels of wild-type kinase in the G2 cause increased inter-centrosome distances with longer spindles, also converging in congression issues. Our findings show that the signals enabling activity of the GRK2/MST2/Nek2A axis for separation also switches on Mdm2 degradation of GRK2 to ensure accurate centrosome dynamics and proper mitotic spindle functionality.


2020 ◽  
Vol 295 (47) ◽  
pp. 16166-16179
Author(s):  
Thao Tran ◽  
Jaba Mitra ◽  
Taekjip Ha ◽  
Jennifer M. Kavran

The Hippo pathway plays an important role in developmental biology, mediating organ size by controlling cell proliferation through the activity of a core kinase cassette. Multiple upstream events activate the pathway, but how each controls this core kinase cassette is not fully understood. Activation of the core kinase cassette begins with phosphorylation of the kinase MST1/2 (also known as STK3/4). Here, using a combination of in vitro biochemistry and cell-based assays, including chemically induced dimerization and single-molecule pulldown, we revealed that increasing the proximity of adjacent kinase domains, rather than formation of a specific protein assembly, is sufficient to trigger autophosphorylation. We validate this mechanism in cells and demonstrate that multiple events associated with the active pathway, including SARAH domain–mediated homodimerization, membrane recruitment, and complex formation with the effector protein SAV1, each increase the kinase domain proximity and autophosphorylation of MST2. Together, our results reveal that multiple and distinct upstream signals each utilize the same common molecular mechanism to stimulate MST2 autophosphorylation. This mechanism is likely conserved among MST2 homologs. Our work also highlights potential differences in Hippo signal propagation between each activating event owing to differences in the dynamics and regulation of each protein ensemble that triggers MST2 autophosphorylation and possible redundancy in activation.


Sign in / Sign up

Export Citation Format

Share Document