scholarly journals DLC1 is a direct target of activated YAP/TAZ that drives collective migration and sprouting angiogenesis

2019 ◽  
Author(s):  
Miesje van der Stoel ◽  
Lilian Schimmel ◽  
Kalim Nawaz ◽  
Anne-Marieke van Stalborch ◽  
Annett de Haan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Cell Polarization ◽  
Fiber Formation ◽  
Collective Migration ◽  
Sprouting Angiogenesis ◽  
Actin Fiber ◽  
Direct Target ◽  
Dlc1 Expression ◽  
Transcriptional Target

AbstractYAP/TAZ signaling is crucial for sprouting angiogenesis and vascular homeostasis through the regulation of endothelial remodeling. Thus far the underlying molecular mechanisms that explain how YAP/TAZ control the vasculature remain unclear. We here identify Deleted-in-Liver-Cancer-1 (DLC1) as a direct transcriptional target of the activated YAP/TAZ-TEAD complex in the endothelium. Substrate stiffening and VEGF stimuli promote the endothelial expression of DLC1. DLC1 expression is dependent on the presence of YAP and TAZ, and constitutive activation of YAP efficiently promotes expression of DLC1. We show that DLC1 limits F-actin fiber formation, integrin-based focal adhesion lifetime and integrin-mediated traction forces. Depletion of endothelial DLC1 strongly perturbs cell polarization in directed collective migration and inhibits the formation of angiogenic sprouts. Importantly, the inability of YAP-depleted endothelial cells to collectively migrate and form angiogenic sprouts can be rescued by ectopic expression of DLC1. Together, these findings reveal that DLC1 fills a hitherto missing link between YAP/TAZ signaling and endothelial dynamics during angiogenesis.

scholarly journals Pax6 regulates granule cell polarization during parallel fiber formation in the developing cerebellum

Development ◽  
2001 ◽  
Vol 128 (16) ◽  
pp. 3133-3144 ◽  
Author(s):  
Takao Yamasaki ◽  
Kousuke Kawaji ◽  
Katsuhiko Ono ◽  
Haruhiko Bito ◽  
Tomoo Hirano ◽  
...  
Keyword(s):  
Granule Cell ◽  
Molecular Mechanisms ◽  
Granule Cells ◽  
Ectopic Expression ◽  
Cell Polarization ◽  
Small Gtpase ◽  
Fiber Formation ◽  
Parallel Fiber ◽  
Differentiation Markers ◽  
Cytoskeletal Organization

The molecular mechanisms that govern the coordinated programs of axonogenesis and cell body migration of the cerebellar granule cell are not well understood. In Pax6 mutant rats(rSey2/rSey2), granule cells in the external germinal layer (EGL) fail to form parallel fiber axons and to migrate tangentially along these fibers despite normal expression of differentiation markers. In culture, mutant cells sprout multiple neurites with enlarged growth cones, suggesting that the absence of Pax6 function perturbs cytoskeletal organization. Some of these alterations are cell-autonomous and rescuable by ectopic expression of Pax6 but not by co-culture with wild-type EGL cells. Cell-autonomous control of cytoskeletal dynamics byPax6 is independent of the ROCK-mediated Rho small GTPase pathway. We propose that in addition to its roles during early patterning of the CNS,Pax6 is involved in a novel regulatory step of cytoskeletal organization during polarization and migration of CNS neurons.

scholarly journals DLC1 is a direct target of activated YAP/TAZ that drives collective migration and sprouting angiogenesis

2020 ◽  
Vol 133 (3) ◽  
pp. jcs239947 ◽  
Author(s):  
Miesje van der Stoel ◽  
Lilian Schimmel ◽  
Kalim Nawaz ◽  
Anne-Marieke van Stalborch ◽  
Annett de Haan ◽  
...  
Keyword(s):  
Collective Migration ◽  
Sprouting Angiogenesis ◽  
Direct Target

scholarly journals Cytoskeleton assembly at endothelial cell–cell contacts is regulated by αII-spectrin–VASP complexes

2008 ◽  
Vol 180 (1) ◽  
pp. 205-219 ◽  
Author(s):  
Peter M. Benz ◽  
Constanze Blume ◽  
Jan Moebius ◽  
Chris Oschatz ◽  
Kai Schuh ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Ectopic Expression ◽  
Sh3 Domain ◽  
Fiber Formation ◽  
Cell Junctions ◽  
Cortical Actin ◽  
Differential Proteomics ◽  
Cell Contacts ◽  
Actin Fiber ◽  
Cell Cell

Directed cortical actin assembly is the driving force for intercellular adhesion. Regulated by phosphorylation, vasodilator-stimulated phosphoprotein (VASP) participates in actin fiber formation. We screened for endothelial proteins, which bind to VASP, dependent on its phosphorylation status. Differential proteomics identified αII-spectrin as such a VASP-interacting protein. αII-Spectrin binds to the VASP triple GP5-motif via its SH3 domain. cAMP-dependent protein kinase–mediated VASP phosphorylation at Ser157 inhibits αII-spectrin–VASP binding. VASP is dephosphorylated upon formation of cell–cell contacts and in confluent, but not in sparse cells, αII-spectrin colocalizes with nonphosphorylated VASP at cell–cell junctions. Ectopic expression of the αII-spectrin SH3 domain at cell–cell contacts translocates VASP, initiates cortical actin cytoskeleton formation, stabilizes cell–cell contacts, and decreases endothelial permeability. Conversely, the permeability of VASP-deficient endothelial cells (ECs) and microvessels of VASP-null mice increases. Reconstitution of VASP-deficient ECs rescues barrier function, whereas αII-spectrin binding-deficient VASP mutants fail to restore elevated permeability. We propose that αII-spectrin–VASP complexes regulate cortical actin cytoskeleton assembly with implications for vascular permeability.

scholarly journals TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Mechanistic Model ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Tissue Samples ◽  
Reporter Assays

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.

scholarly journals The Phosphatidylserine Receptor TIM-1 Enhances Authentic Chikungunya Virus Cell Entry

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1828
Author(s):  
Jared Kirui ◽  
Yara Abidine ◽  
Annasara Lenman ◽  
Koushikul Islam ◽  
Yong-Dae Gwon ◽  
...  
Keyword(s):  
Chikungunya Virus ◽  
Molecular Mechanisms ◽  
Rna Virus ◽  
Ectopic Expression ◽  
Point Mutations ◽  
Cell Entry ◽  
Target Cells ◽  
Human Hepatoma Cells ◽  
Chikv Infection ◽  
Phosphatidylserine Receptor

Chikungunya virus (CHIKV) is a re-emerging, mosquito-transmitted, enveloped positive stranded RNA virus. Chikungunya fever is characterized by acute and chronic debilitating arthritis. Although multiple host factors have been shown to enhance CHIKV infection, the molecular mechanisms of cell entry and entry factors remain poorly understood. The phosphatidylserine-dependent receptors, T-cell immunoglobulin and mucin domain 1 (TIM-1) and Axl receptor tyrosine kinase (Axl), are transmembrane proteins that can serve as entry factors for enveloped viruses. Previous studies used pseudoviruses to delineate the role of TIM-1 and Axl in CHIKV entry. Conversely, here, we use the authentic CHIKV and cells ectopically expressing TIM-1 or Axl and demonstrate a role for TIM-1 in CHIKV infection. To further characterize TIM-1-dependent CHIKV infection, we generated cells expressing domain mutants of TIM-1. We show that point mutations in the phosphatidylserine binding site of TIM-1 lead to reduced binding, entry, and infection of CHIKV. Ectopic expression of TIM-1 renders immortalized keratinocytes permissive to CHIKV, whereas silencing of endogenously expressed TIM-1 in human hepatoma cells reduces CHIKV infection. Altogether, our findings indicate that, unlike Axl, TIM-1 readily promotes the productive entry of authentic CHIKV into target cells.

scholarly journals EpCAM promotes endosomal modulation of the cortical RhoA zone for epithelial organization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cécile Gaston ◽  
Simon De Beco ◽  
Bryant Doss ◽  
Meng Pan ◽  
Estelle Gauquelin ◽  
...  
Keyword(s):  
Cell Shape ◽  
Specific Protein ◽  
Cell Polarization ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Endosomal Trafficking ◽  
Transient Zone ◽  
And Behavior ◽  
Fine Tune

AbstractAt the basis of cell shape and behavior, the organization of actomyosin and its ability to generate forces are widely studied. However, the precise regulation of this contractile network in space and time is unclear. Here, we study the role of the epithelial-specific protein EpCAM, a contractility modulator, in cell shape and motility. We show that EpCAM is required for stress fiber generation and front-rear polarity acquisition at the single cell level. In fact, EpCAM participates in the remodeling of a transient zone of active RhoA at the cortex of spreading epithelial cells. EpCAM and RhoA route together through the Rab35/EHD1 fast recycling pathway. This endosomal pathway spatially organizes GTP-RhoA to fine tune the activity of actomyosin resulting in polarized cell shape and development of intracellular stiffness and traction forces. Impairment of GTP-RhoA endosomal trafficking either by silencing EpCAM or by expressing Rab35/EHD1 mutants prevents proper myosin-II activity, stress fiber formation and ultimately cell polarization. Collectively, this work shows that the coupling between co-trafficking of EpCAM and RhoA, and actomyosin rearrangement is pivotal for cell spreading, and advances our understanding of how biochemical and mechanical properties promote cell plasticity.

scholarly journals Identification of Nucleolin as a Novel AEG-1-Interacting Protein in Breast Cancer via Interactome Profiling

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2842
Author(s):  
Seong-Jae Lee ◽  
Kyoung-Min Choi ◽  
Geul Bang ◽  
Seo-Gyu Park ◽  
Eun-Bi Kim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Cells ◽  
Molecular Mechanisms ◽  
Affinity Purification ◽  
Ectopic Expression ◽  
Cancer Cell Proliferation ◽  
Breast Cancer Cell Proliferation ◽  
Interacting Protein ◽  
Proliferation And Invasion ◽  
Oncogenic Function

Breast cancer is one of the most common malignant diseases worldwide. Astrocyte elevated gene-1 (AEG-1) is upregulated in breast cancer and regulates breast cancer cell proliferation and invasion. However, the molecular mechanisms by which AEG-1 promotes breast cancer have yet to be fully elucidated. In order to delineate the function of AEG-1 in breast cancer development, we mapped the AEG-1 interactome via affinity purification followed by LC-MS/MS. We identified nucleolin (NCL) as a novel AEG-1 interacting protein, and co-immunoprecipitation experiments validated the interaction between AEG-1 and NCL in breast cancer cells. The silencing of NCL markedly reduced not only migration/invasion, but also the proliferation induced by the ectopic expression of AEG-1. Further, we found that the ectopic expression of AEG-1 induced the tyrosine phosphorylation of c-Met, and NCL knockdown markedly reduced this AEG-1 mediated phosphorylation. Taken together, our report identifies NCL as a novel mediator of the oncogenic function of AEG-1, and suggests that c-Met could be associated with the oncogenic function of the AEG-1-NCL complex in the context of breast cancer.

scholarly journals LATERAL FLORET 1 induced the three-florets spikelet in rice

2017 ◽  
Vol 114 (37) ◽  
pp. 9984-9989 ◽  
Author(s):  
Ting Zhang ◽  
Yunfeng Li ◽  
Ling Ma ◽  
Xianchun Sang ◽  
Yinghua Ling ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Target Sequence ◽  
Class Iii ◽  
Rice Mutant ◽  
Inflorescence Structure ◽  
Meristem Maintenance ◽  
Floral Meristems ◽  
Sterile Lemma

The spikelet is a unique inflorescence structure in grass. The molecular mechanisms behind the development and evolution of the spikelet are far from clear. In this study, a dominant rice mutant, lateral florets 1 (lf1), was characterized. In the lf1 spikelet, lateral floral meristems were promoted unexpectedly and could generally blossom into relatively normal florets. LF1 encoded a class III homeodomain-leucine zipper (HD-ZIP III) protein, and the site of mutation in lf1 was located in a putative miRNA165/166 target sequence. Ectopic expression of both LF1 and the meristem maintenance gene OSH1 was detected in the axil of the sterile lemma primordia of the lf1 spikelet. Furthermore, the promoter of OSH1 could be bound directly by LF1 protein. Collectively, these results indicate that the mutation of LF1 induces ectopic expression of OSH1, which results in the initiation of lateral meristems to generate lateral florets in the axil of the sterile lemma. This study thus offers strong evidence in support of the “three-florets spikelet” hypothesis in rice.

scholarly journals MicroRNA-342 Prohibits Proliferation and Invasion of Melanoma Cells by Directly Targeting Zinc-Finger E-Box-Binding Homeobox 1

2018 ◽  
Vol 26 (9) ◽  
pp. 1447-1455 ◽  
Author(s):  
Quan Shi ◽  
Qi He ◽  
Jing Wei
Keyword(s):  
Cell Proliferation ◽  
Zinc Finger ◽  
Ectopic Expression ◽  
Melanoma Cells ◽  
Potential Candidate ◽  
E Box ◽  
Direct Target Gene ◽  
Direct Target ◽  
Proliferation And Invasion ◽  
Zeb1 Expression

As documented in numerous studies, microRNAs (miRNAs) play key roles in various biological processes associated with melanoma occurrence and development. In this study, we found that miRNA-342 (miR-342) was significantly downregulated in melanoma tissues and cell lines. Additionally, the ectopic expression of miR-342 prohibited the cell proliferation and invasion of melanoma. Moreover, zinc-finger E-box-binding homeobox 1 (ZEB1) was identified as a direct target gene of miR-342 in melanoma. Similar with the results induced by miR-342 overexpression, ZEB1 knockdown attenuated cell proliferation and invasion in melanoma. Furthermore, the restoration of ZEB1 expression reversed the suppressive effects of miR-342 on the proliferation and invasion of melanoma cells. These findings suggest that miR-342 may play tumor-suppressing roles in melanoma, at least partially, by directly inhibiting ZEB1 expression. Therefore, miR-342 may be developed as a potential candidate for the treatment of patients with this aggressive type of cancer.

scholarly journals SPNS2 Downregulation Induces EMT and Promotes Colorectal Cancer Metastasis via Activating AKT Signaling Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Lei Lv ◽  
Qiyi Yi ◽  
Ying Yan ◽  
Fengmei Chao ◽  
Ming Li
Keyword(s):  
Colorectal Cancer ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Migration And Invasion ◽  
Akt Inhibitor ◽  
Colon Adenoma ◽  
Mesenchymal Transition

Spinster homologue 2 (SPNS2), a transporter of S1P (sphingosine-1-phosphate), has been reported to mediate immune response, vascular development, and pathologic processes of diseases such as cancer via S1P signaling pathways. However, its biological functions and expression profile in colorectal cancer (CRC) is elusive. In this study, we disclosed that SPNS2 expression, which was regulated by copy number variation and DNA methylation of its promoter, was dramatically upregulated in colon adenoma and CRC compared to normal tissues. However, its expression was lower in CRC than in colon adenoma, and low expression of SPN2 correlated with advanced T/M/N stage and poor prognosis in CRC. Ectopic expression of SPNS2 inhibited cell proliferation, migration, epithelial–mesenchymal transition (EMT), invasion, and metastasis in CRC cell lines, while silencing SPNS2 had the opposite effects. Meanwhile, measuring the intracellular and extracellular level of S1P after overexpression of SPNS2 pinpointed a S1P-independent model of SPNS2. Mechanically, SPNS2 led to PTEN upregulation and inactivation of Akt. Moreover, AKT inhibitor (MK2206) abrogated SPNS2 knockdown-induced promoting effects on the migration and invasion, while AKT activator (SC79) reversed the repression of migration and invasion by SPNS2 overexpression in CRC cells, confirming the pivotal role of AKT for SPNS2’s function. Collectively, our study demonstrated the suppressor role of SPNS2 during CRC metastasis, providing new insights into the pathology and molecular mechanisms of CRC progression.

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