scholarly journals The palmitoyltransferase Approximated promotes growth via the Hippo pathway by palmitoylation of Fat

2016 ◽  
Vol 216 (1) ◽  
pp. 265-277 ◽  
Author(s):  
Hitoshi Matakatsu ◽  
Seth S. Blair ◽  
Richard G. Fehon
Keyword(s):  
Posttranslational Modification ◽  
Hippo Pathway ◽  
Growth Control ◽  
Tissue Growth ◽  
Negative Regulator ◽  
Pathway Activity ◽  
Protein Association ◽  
Junctional Region ◽  
Growth Loss ◽  
The Hippo Pathway

The large protocadherin Fat functions to promote Hippo pathway activity in restricting tissue growth. Loss of Fat leads to accumulation of the atypical myosin Dachs at the apical junctional region, which in turn promotes growth by inhibiting Warts. We previously identified Approximated (App), a DHHC domain palmitoyltransferase, as a negative regulator of Fat signaling in growth control. We show here that App promotes growth by palmitoylating the intracellular domain of Fat, and that palmitoylation negatively regulates Fat function. Independently, App also recruits Dachs to the apical junctional region through protein–protein association, thereby stimulating Dachs’s activity in promoting growth. Further, we show that palmitoylation by App functions antagonistically to phosphorylation by Discs-overgrown, which activates Fat. Together, these findings suggest a model in which App promotes Dachs activity by simultaneously repressing Fat via posttranslational modification and recruiting Dachs to the apical junctional region, thereby promoting tissue growth.

scholarly journals Genome-Wide Screen for Context-Dependent Tumor Suppressors Identified Using in Vivo Models for Neoplasia in Drosophila

2020 ◽  
Vol 10 (9) ◽  
pp. 2999-3008 ◽  
Author(s):  
Casper Groth ◽  
Pooja Vaid ◽  
Aditi Khatpe ◽  
Nelchi Prashali ◽  
Avantika Ahiya ◽  
...  
Keyword(s):  
Large Scale ◽  
Hippo Pathway ◽  
Growth Control ◽  
Growth Factor Receptor ◽  
Tissue Growth ◽  
In Vivo Models ◽  
Genome Wide ◽  
Positive Regulators ◽  
The Hippo Pathway

Abstract Genetic approaches in Drosophila have successfully identified many genes involved in regulation of growth control as well as genetic interactions relevant to the initiation and progression of cancer in vivo. Here, we report on large-scale RNAi-based screens to identify potential tumor suppressor genes that interact with known cancer-drivers: the Epidermal Growth Factor Receptor and the Hippo pathway transcriptional cofactor Yorkie. These screens were designed to identify genes whose depletion drove tissue expressing EGFR or Yki from a state of benign overgrowth into neoplastic transformation in vivo. We also report on an independent screen aimed to identify genes whose depletion suppressed formation of neoplastic tumors in an existing EGFR-dependent neoplasia model. Many of the positives identified here are known to be functional in growth control pathways. We also find a number of novel connections to Yki and EGFR driven tissue growth, mostly unique to one of the two. Thus, resources provided here would be useful to all researchers who study negative regulators of growth during development and cancer in the context of activated EGFR and/or Yki and positive regulators of growth in the context of activated EGFR. Resources reported here are available freely for anyone to use.

scholarly journals The miRNA bantam regulates growth and tumorigenesis by repressing the cell cycle regulator tribbles

2019 ◽  
Vol 2 (4) ◽  
pp. e201900381 ◽  
Author(s):  
Stephan U Gerlach ◽  
Moritz Sander ◽  
Shilin Song ◽  
Héctor Herranz
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Target Genes ◽  
Hippo Pathway ◽  
Growth Control ◽  
Tissue Growth ◽  
Tumor Formation ◽  
Hippo Signaling ◽  
Cell Cycle Regulators ◽  
The Hippo Pathway

One of the fundamental issues in biology is understanding how organ size is controlled. Tissue growth has to be carefully regulated to generate well-functioning organs, and defects in growth control can result in tumor formation. The Hippo signaling pathway is a universal growth regulator and has been implicated in cancer. In Drosophila, the Hippo pathway acts through the miRNA bantam to regulate cell proliferation and apoptosis. Even though the bantam targets regulating apoptosis have been determined, the target genes controlling proliferation have not been identified thus far. In this study, we identify the gene tribbles as a direct bantam target gene. Tribbles limits cell proliferation by suppressing G2/M transition. We show that tribbles regulation by bantam is central in controlling tissue growth and tumorigenesis. We expand our study to other cell cycle regulators and show that deregulated G2/M transition can collaborate with oncogene activation driving tumor formation.

scholarly journals Amotl2a interacts with the Hippo effector Yap1 and the Wnt/β-catenin effector Lef1 to control tissue size in zebrafish

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Sobhika Agarwala ◽  
Sandra Duquesne ◽  
Kun Liu ◽  
Anton Boehm ◽  
Lin Grimm ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Growth Control ◽  
Tissue Growth ◽  
Cell Junction ◽  
Hippo Signaling ◽  
Sensory Organs ◽  
Hippo Signaling Pathway ◽  
Tissue Size ◽  
The Hippo Pathway ◽  
First Time

During development, proliferation must be tightly controlled for organs to reach their appropriate size. While the Hippo signaling pathway plays a major role in organ growth control, how it senses and responds to increased cell density is still unclear. In this study, we use the zebrafish lateral line primordium (LLP), a group of migrating epithelial cells that form sensory organs, to understand how tissue growth is controlled during organ formation. Loss of the cell junction-associated Motin protein Amotl2a leads to overproliferation and bigger LLP, affecting the final pattern of sensory organs. Amotl2a function in the LLP is mediated together by the Hippo pathway effector Yap1 and the Wnt/β-catenin effector Lef1. Our results implicate for the first time the Hippo pathway in size regulation in the LL system. We further provide evidence that the Hippo/Motin interaction is essential to limit tissue size during development.

scholarly journals The transcriptional co-repressor CtBP is a negative regulator of growth that antagonizes the Yorkie and JNK/AP-1 pathways

2019 ◽  
Author(s):  
Taryn M. Sumabat ◽  
Melanie I. Worley ◽  
Brett J. Pellock ◽  
Justin A. Bosch ◽  
Iswar K. Hariharan
Keyword(s):  
Mammalian Cells ◽  
Growth Regulation ◽  
Hippo Pathway ◽  
Growth Control ◽  
Tissue Growth ◽  
Negative Regulator ◽  
Control Mechanisms ◽  
Loss Of Function ◽  
Jnk Pathway ◽  
Multicellular Organisms

AbstractMulticellular organisms require strict growth control mechanisms to ensure that an organ reaches, but does not grossly exceed, its appropriate size and shape. In an unbiased mosaic screen for genes involved in growth regulation, we identified a loss-of-function allele of the gene CtBP that conferred a growth advantage to homozygous mutant tissue. CtBP encodes a transcriptional co-repressor found in diverse organisms, yet its role in regulating tissue growth is not known. We found that CtBP functions as a negative regulator of growth by restricting the expression of the growth-promoting microRNA bantam (ban). ban is a known target of the Hippo pathway effector Yorkie (Yki). We show that loss of CtBP function leads to the activation of a minimal enhancer of ban via both Yki-dependent and AP-1 transcription factor-dependent mechanisms. AP-1 is downstream of the Jun N-terminal Kinase (JNK) pathway and thus JNK could regulate growth during development via ban. Furthermore, we show that distinct isoforms of the AP-1 component Fos differ in their ability to activate this enhancer. Since the orthologous pathways in mammalian cells (YAP/TEAD and AP-1) converge on enhancers implicated in tumor progression, a role for mammalian CtBP proteins at those enhancers merits attention.

scholarly journals Inactivation of YAP oncoprotein by the Hippo pathway is involved in cell contact inhibition and tissue growth control

2007 ◽  
Vol 21 (21) ◽  
pp. 2747-2761 ◽  
Author(s):  
B. Zhao ◽  
X. Wei ◽  
W. Li ◽  
R. S. Udan ◽  
Q. Yang ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Growth Control ◽  
Tissue Growth ◽  
Contact Inhibition ◽  
Cell Contact ◽  
The Hippo Pathway

scholarly journals Genome-wide RNAi screen for context-dependent tumor suppressors identified using in vivo models for neoplasia in Drosophila

2019 ◽  
Author(s):  
Casper Groth ◽  
Pooja Vaid ◽  
Aditi Khatpe ◽  
Nelchi Prashali ◽  
Avantika Ahiya ◽  
...  
Keyword(s):  
Large Scale ◽  
Hippo Pathway ◽  
Growth Control ◽  
Growth Factor Receptor ◽  
Tissue Growth ◽  
In Vivo Models ◽  
Genome Wide ◽  
Positive Regulators ◽  
The Hippo Pathway

AbstractGenetic approaches in Drosophila have successfully identified many genes involved in regulation of growth control as well as genetic interactions relevant to the initiation and progression of cancer in vivo. Here, we report on large-scale RNAi-based screens to identify potential tumor suppressor genes that interact with known cancer-drivers: The Epidermal Growth Factor Receptor and the Hippo pathway transcriptional cofactor Yorkie. These screens were designed to identify genes whose depletion drove tissue expressing EGFR or Yki from a state of benign overgrowth into neoplastic transformation in vivo. We also report on an independent screen aimed to identify genes whose depletion suppressed formation of neoplastic tumors in an existing EGFR-dependent neoplasia model. Many of the positives identified here are known to be functional in growth control pathways. We also find a number of novel connections to Yki and EGFR driven tissue growth, mostly unique to one of the two. Thus, resources provided here would be useful to all researchers who study negative regulators of growth in the context of activated EGFR and/or Yki and positive regulators of growth in the context of activated EGFR.

scholarly journals NPHP4, a cilia-associated protein, negatively regulates the Hippo pathway

2011 ◽  
Vol 193 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Sandra Habbig ◽  
Malte P. Bartram ◽  
Roman U. Müller ◽  
Ricarda Schwarz ◽  
Nikolaos Andriopoulos ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cellular Proliferation ◽  
Nuclear Translocation ◽  
Hippo Pathway ◽  
Negative Regulator ◽  
Hippo Signaling ◽  
Transcriptional Coactivator ◽  
Hippo Signaling Pathway ◽  
The Hippo Pathway ◽  
Potent Negative Regulator

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.

scholarly journals Want to promote tissue growth? There’s an App for that!

2016 ◽  
Vol 216 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Ben Short
Keyword(s):  
Hippo Pathway ◽  
Tissue Growth ◽  
The Hippo Pathway

Study describes how a palmitoyltransferase regulates the Hippo pathway in flies.

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.

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