scholarly journals Role for Merlin/NF2 in transcription elongation through interaction with the PAF complex

2019 ◽  
Author(s):  
Anne E. Roehrig ◽  
Kristina Klupsch ◽  
Juan A. Oses-Prieto ◽  
Selim Chaib ◽  
Stephen Henderson ◽  
...  
Keyword(s):  
Transcription Elongation ◽  
Hippo Pathway ◽  
Contact Inhibition ◽  
Tumour Suppressor ◽  
Cell Cortex ◽  
Dependent Manner ◽  
A Cell ◽  
The Hippo Pathway ◽  
Inactivating Mutations ◽  
Paf Complex

SUMMARYThe PAF complex (PAFC) coordinates transcription elongation and mRNA processing events and its CDC73/parafibromin subunit functions as a tumour suppressor. The NF2/Merlin tumour suppressor functions at the cell cortex and nucleus and is a key mediator of contact inhibition. Here we provide a direct link between nuclear Merlin and transcription elongation controlled by cell-cell adhesion. Merlin interacts with the PAFC in a cell density-dependent manner and tumour-derived inactivating mutations in both Merlin and CDC73 mutually disrupt their interaction. Growth suppression by Merlin requires CDC73 and Merlin regulates PAFC association with chromatin in a subset of genes. We also identify by CDC73 affinity-proteomics a role for FAT cadherins in regulating the Merlin-PAFC interaction. Our results suggest that in addition to its function within the Hippo pathway, nuclear Merlin is part of a tumour suppressor network which coordinates postinitiation steps of the transcription cycle of genes mediating in contact inhibition.

scholarly journals Cell-cell adhesion regulates Merlin/NF2 interaction with the PAF complex

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254697
Author(s):  
Anne E. Roehrig ◽  
Kristina Klupsch ◽  
Juan A. Oses-Prieto ◽  
Selim Chaib ◽  
Stephen Henderson ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Molecular Mechanisms ◽  
Hippo Pathway ◽  
Contact Inhibition ◽  
Tumour Suppressor ◽  
Cell Cortex ◽  
Dependent Manner ◽  
A Cell ◽  
Cell Cell ◽  
Paf Complex

The PAF complex (PAFC) coordinates transcription elongation and mRNA processing and its CDC73/parafibromin subunit functions as a tumour suppressor. The NF2/Merlin tumour suppressor functions both at the cell cortex and nucleus and is a key mediator of contact inhibition but the molecular mechanisms remain unclear. In this study we have used affinity proteomics to identify novel Merlin interacting proteins and show that Merlin forms a complex with multiple proteins involved in RNA processing including the PAFC and the CHD1 chromatin remodeller. Tumour-derived inactivating mutations in both Merlin and the CDC73 PAFC subunit mutually disrupt their interaction and growth suppression by Merlin requires CDC73. Merlin interacts with the PAFC in a cell density-dependent manner and we identify a role for FAT cadherins in regulating the Merlin-PAFC interaction. Our results suggest that in addition to its function within the Hippo pathway, Merlin is part of a tumour suppressor network regulated by cell-cell adhesion which coordinates post-initiation steps of the transcription cycle of genes mediating contact inhibition.

scholarly journals Activating Hippo Pathway via Rassf1 by Ursolic Acid Suppresses the Tumorigenesis of Gastric Cancer

2019 ◽  
Vol 20 (19) ◽  
pp. 4709 ◽  
Author(s):  
Seong-Hun Kim ◽  
Hua Jin ◽  
Ruo Yu Meng ◽  
Da-Yeah Kim ◽  
Yu Chuan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Cancer Cells ◽  
Ursolic Acid ◽  
Hippo Pathway ◽  
Dependent Manner ◽  
Gastric Cancer Cells ◽  
Protein Levels ◽  
Tumor Tissues ◽  
The Hippo Pathway

The Hippo pathway is often dysregulated in many carcinomas, which results in various stages of tumor progression. Ursolic acid (UA), a natural compound that exists in many herbal plants, is known to obstruct cancer progression and exerts anti-carcinogenic effect on a number of human cancers. In this study, we aimed to examine the biological mechanisms of action of UA through the Hippo pathway in gastric cancer cells. MTT assay showed a decreased viability of gastric cancer cells after treatment with UA. Following treatment with UA, colony numbers and the sizes of gastric cancer cells were significantly diminished and apoptosis was observed in SNU484 and SNU638 cells. The invasion and migration rates of gastric cancer cells were suppressed by UA in a dose-dependent manner. To further determine the gene expression patterns that are related to the effects of UA, a microarray analysis was performed. Gene ontology analysis revealed that several genes, such as the Hippo pathway upstream target gene, ras association domain family (RASSF1), and its downstream target genes (MST1, MST2, and LATS1) were significantly upregulated by UA, while the expression of YAP1 gene, together with oncogenes (FOXM1, KRAS, and BATF), were significantly decreased. Similar to the gene expression profiling results, the protein levels of RASSF1, MST1, MST2, LATS1, and p-YAP were increased, whereas those of CTGF were decreased by UA in gastric cancer cells. The p-YAP expression induced in gastric cancer cells by UA was reversed with RASSF1 silencing. In addition, the protein levels in the Hippo pathway were increased in the UA-treated xenograft tumor tissues as compared with that in the control tumor tissues; thus, UA significantly inhibited the tumorigenesis of gastric cancer in vivo in xenograft animals. Collectively, UA diminishes the proliferation and metastasis of gastric cancer via the regulation of Hippo pathway through Rassf1, which suggests that UA can be used as a potential chemopreventive and therapeutic agent for gastric cancer.

scholarly journals α-Tubulin K40 acetylation is required for contact inhibition of proliferation and cell–substrate adhesion

2014 ◽  
Vol 25 (12) ◽  
pp. 1854-1866 ◽  
Author(s):  
Andrea Aguilar ◽  
Lars Becker ◽  
Thomas Tedeschi ◽  
Stefan Heller ◽  
Carlo Iomini ◽  
...  
Keyword(s):  
Cell Density ◽  
Hippo Pathway ◽  
Focal Adhesions ◽  
Contact Inhibition ◽  
Inhibition Of Proliferation ◽  
Genetic Ablation ◽  
Substrate Adhesion ◽  
Cell Substrate ◽  
The Hippo Pathway ◽  
Cell Substrate Adhesion

Acetylation of α-tubulin on lysine 40 marks long-lived microtubules in structures such as axons and cilia, and yet the physiological role of α-tubulin K40 acetylation is elusive. Although genetic ablation of the α-tubulin K40 acetyltransferase αTat1 in mice did not lead to detectable phenotypes in the developing animals, contact inhibition of proliferation and cell–substrate adhesion were significantly compromised in cultured αTat1−/− fibroblasts. First, αTat1−/− fibroblasts kept proliferating beyond the confluent monolayer stage. Congruently, αTat1−/− cells failed to activate Hippo signaling in response to increased cell density, and the microtubule association of the Hippo regulator Merlin was disrupted. Second, αTat1−/− cells contained very few focal adhesions, and their ability to adhere to growth surfaces was greatly impaired. Whereas the catalytic activity of αTAT1 was dispensable for monolayer formation, it was necessary for cell adhesion and restrained cell proliferation and activation of the Hippo pathway at elevated cell density. Because α-tubulin K40 acetylation is largely eliminated by deletion of αTAT1, we propose that acetylated microtubules regulate contact inhibition of proliferation through the Hippo pathway.

scholarly journals Australin: a chromosomal passenger protein required specifically for Drosophila melanogaster male meiosis

2008 ◽  
Vol 180 (3) ◽  
pp. 521-535 ◽  
Author(s):  
Shan Gao ◽  
Maria Grazia Giansanti ◽  
Graham J. Buttrick ◽  
Sharada Ramasubramanyan ◽  
Adam Auton ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Male Meiosis ◽  
Cell Cortex ◽  
Dependent Manner ◽  
Spindle Formation ◽  
Chromatid Cohesion ◽  
Chromosome Alignment ◽  
Chromosomal Passenger ◽  
A Cell ◽  
Cycle Dependent

The chromosomal passenger complex (CPC), which is composed of conserved proteins aurora B, inner centromere protein (INCENP), survivin, and Borealin/DASRA, localizes to chromatin, kinetochores, microtubules, and the cell cortex in a cell cycle–dependent manner. The CPC is required for multiple aspects of cell division. Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust). Although Borr is a passenger in all mitotic tissues studied, it is specifically replaced by Aust for the two male meiotic divisions. We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC. Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation. Furthermore, we show that the CPC is required earlier in cytokinesis than previously thought; cells lacking Aust do not initiate central spindle formation, accumulate anillin or actin at the cell equator, or undergo equatorial constriction.

scholarly journals MINDY1 promotes bladder cancer progression by stabilizing YAP

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yongwen Luo ◽  
Jun Zhou ◽  
Jianing Tang ◽  
Fengfang Zhou ◽  
Zhiwen He ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cancer Progression ◽  
Target Genes ◽  
Hippo Pathway ◽  
Tumor Model ◽  
Dependent Manner ◽  
Interaction Domain ◽  
Bona Fide ◽  
The Hippo Pathway

Abstract Background Bladder cancer is one of the most commonly diagnosed urological malignant tumor. The Hippo tumor suppressor pathway is highly conserved in mammals and plays an important role in carcinogenesis. YAP is one of major key effectors of the Hippo pathway. However, the mechanism supporting abnormal YAP expression in bladder cancer remains to be characterized. Methods Western blot was used to measure the expression of MINDY1 and YAP, while the YAP target genes were measured by real-time PCR. CCK8 assay was used to detect the cell viability. The xeno-graft tumor model was used for in vivo study. Protein stability assay was used to detect YAP protein degradation. Immuno-precipitation assay was used to detect the interaction domain between MINDY1 and YAP. The ubiquitin-based Immuno-precipitation assays were used to detect the specific ubiquitination manner happened on YAP. Results In the present study, we identified MINDY1, a DUB enzyme in the motif interacting with ubiquitin-containing novel DUB family, as a bona fide deubiquitylase of YAP in bladder cancer. MINDY1 was shown to interact with, deubiquitylate, and stabilize YAP in a deubiquitylation activity-dependent manner. MINDY1 depletion significantly decreased bladder cancer cell proliferation. The effects induced by MINDY1 depletion could be rescued by further YAP overexpression. Depletion of MINDY1 decreased the YAP protein level and the expression of YAP/TEAD target genes in bladder cancer, including CTGF, ANKRD1 and CYR61. Conclusion In general, our findings establish a previously undocumented catalytic role for MINDY1 as a deubiquitinating enzyme of YAP and provides a possible target for the therapy of bladder cancer.

scholarly journals Nerfin-1 represses transcriptional output of Hippo signaling in cell competition

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Pengfei Guo ◽  
Chang-Hyun Lee ◽  
Huiyan Lei ◽  
Yonggang Zheng ◽  
Katiuska Daniela Pulgar Prieto ◽  
...  
Keyword(s):  
Dna Binding ◽  
Hippo Pathway ◽  
Ectopic Expression ◽  
Tissue Growth ◽  
Hippo Signaling ◽  
Dependent Manner ◽  
Cell Competition ◽  
Regulatory Mode ◽  
The Hippo Pathway ◽  
Transcriptional Output

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.

A cell-based assay to screen stimulators of the Hippo pathway reveals the inhibitory effect of dobutamine on the YAP-dependent gene transcription

2011 ◽  
Vol 150 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Y. Bao ◽  
K. Nakagawa ◽  
Z. Yang ◽  
M. Ikeda ◽  
K. Withanage ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Hippo Pathway ◽  
Inhibitory Effect ◽  
A Cell ◽  
The Hippo Pathway
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