scholarly journals Pulsed actomyosin contractions in morphogenesis

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 142 ◽  
Author(s):  
Ann Sutherland ◽  
Alyssa Lesko
Keyword(s):  
Cell Shape ◽  
Normal Development ◽  
Tissue Growth ◽  
Model Systems ◽  
Cellular Processes ◽  
Cytoskeletal Networks ◽  
And Migration ◽  
Shape Changes

Cell and tissue shape changes are the fundamental elements of morphogenesis that drive normal development of embryos into fully functional organisms. This requires a variety of cellular processes including establishment and maintenance of polarity, tissue growth and apoptosis, and cell differentiation, rearrangement, and migration. It is widely appreciated that the cytoskeletal networks play an important role in regulating many of these processes and, in particular, that pulsed actomyosin contractions are a core cellular mechanism driving cell shape changes and cell rearrangement. In this review, we discuss the role of pulsed actomyosin contractions during developmental morphogenesis, advances in our understanding of the mechanisms regulating actomyosin pulsing, and novel techniques to probe the role of pulsed actomyosin processes in in vivo model systems.

scholarly journals Group I PAKs function downstream of Rac to promote podosome invasion during myoblast fusion in vivo

2012 ◽  
Vol 199 (1) ◽  
pp. 169-185 ◽  
Author(s):  
Rui Duan ◽  
Peng Jin ◽  
Fengbao Luo ◽  
Guofeng Zhang ◽  
Nathan Anderson ◽  
...  
Keyword(s):  
Cell Shape ◽  
Myoblast Fusion ◽  
Small Gtpase ◽  
Fusion Pore ◽  
Cellular Processes ◽  
Filament Assembly ◽  
Group I ◽  
Redundant Functions ◽  
Shape Changes

The p21-activated kinases (PAKs) play essential roles in diverse cellular processes and are required for cell proliferation, apoptosis, polarity establishment, migration, and cell shape changes. Here, we have identified a novel function for the group I PAKs in cell–cell fusion. We show that the two Drosophila group I PAKs, DPak3 and DPak1, have partially redundant functions in myoblast fusion in vivo, with DPak3 playing a major role. DPak3 is enriched at the site of fusion colocalizing with the F-actin focus within a podosome-like structure (PLS), and promotes actin filament assembly during PLS invasion. Although the small GTPase Rac is involved in DPak3 activation and recruitment to the PLS, the kinase activity of DPak3 is required for effective PLS invasion. We propose a model whereby group I PAKs act downstream of Rac to organize the actin filaments within the PLS into a dense focus, which in turn promotes PLS invasion and fusion pore initiation during myoblast fusion.

Functional analysis of the SUMOylation pathway in Drosophila

2008 ◽  
Vol 36 (5) ◽  
pp. 868-873 ◽  
Author(s):  
Ana Talamillo ◽  
Jonatan Sánchez ◽  
Rosa Barrio
Keyword(s):  
Functional Analysis ◽  
Fine Tuning ◽  
Model Systems ◽  
Post Translational Modification ◽  
Reversible Process ◽  
Cellular Processes ◽  
Tuning Mechanism ◽  
Sumo Conjugation

SUMOylation, a reversible process used as a ‘fine-tuning’ mechanism to regulate the role of multiple proteins, is conserved throughout evolution. This post-translational modification affects several cellular processes by the modulation of subcellular localization, activity or stability of a variety of substrates. A growing number of proteins have been identified as targets for SUMOylation, although, for many of them, the role of SUMO conjugation on their function is unknown. The use of model systems might facilitate the study of SUMOylation implications in vivo. In the present paper, we have compiled what is known about SUMOylation in Drosophila melanogaster, where the use of genetics provides new insights on SUMOylation's biological roles.

scholarly journals Using Bcr-Abl to Examine Mechanisms by Which Abl Kinase Regulates Morphogenesis in Drosophila

2008 ◽  
Vol 19 (1) ◽  
pp. 378-393 ◽  
Author(s):  
Traci L. Stevens ◽  
Edward M. Rogers ◽  
Laura M. Koontz ◽  
Donald T. Fox ◽  
Catarina C.F. Homem ◽  
...  
Keyword(s):  
Cell Shape ◽  
Normal Development ◽  
Wild Type ◽  
Nonreceptor Tyrosine Kinase ◽  
Abl Kinase ◽  
Embryonic Morphogenesis ◽  
Dose Dependent ◽  
Shape Changes ◽  
Insight Into

Signaling by the nonreceptor tyrosine kinase Abelson (Abl) plays key roles in normal development, whereas its inappropriate activation helps trigger the development of several forms of leukemia. Abl is best known for its roles in axon guidance, but Abl and its relatives also help regulate embryonic morphogenesis in epithelial tissues. Here, we explore the role of regulation of Abl kinase activity during development. We first compare the subcellular localization of Abl protein and of active Abl, by using a phosphospecific antibody, providing a catalog of places where Abl is activated. Next, we explore the consequences for morphogenesis of overexpressing wild-type Abl or expressing the activated form found in leukemia, Bcr-Abl. We find dose-dependent effects of elevating Abl activity on morphogenetic movements such as head involution and dorsal closure, on cell shape changes, on cell protrusive behavior, and on the organization of the actin cytoskeleton. Most of the effects of Abl activation parallel those caused by reduction in function of its target Enabled. Abl activation leads to changes in Enabled phosphorylation and localization, suggesting a mechanism of action. These data provide new insight into how regulated Abl activity helps direct normal development and into possible biological functions of Bcr-Abl.

scholarly journals Mitogen Kinase Kinase (MKK7) controls cytokine production in vitro and in vivo in mice

2021 ◽  
Author(s):  
Amada D. Caliz ◽  
Hyung-Jin Yoo ◽  
Anastassiia Vertii ◽  
Cathy Tournier ◽  
Roger J. Davis ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Cell Types ◽  
Minor Role ◽  
Cellular Processes ◽  
Mitogen Activated Protein ◽  
And Migration ◽  
Jnk Activation

Mitogen kinase kinase 4 (MKK4) and Mitogen kinase kinase 7 (MKK7) are members of the MAP2K family which can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both, c-Jun N-terminal Kinase (JNK) and p38 MAPK, whereas MKK7 only activates JNK in response to different stimuli. The stimuli as well as cell type determine the choice of MAP2K member that mediates the response. In a variety of cell types, the MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK7 and MKK4 contributes to innate immune response in macrophages as well as during inflammation in vivo. To address this question and elucidate the role of MKK7 and MKK4 in macrophage and in vivo, we developed MKK7- and MKK4-deficient mouse models with tamoxifen-inducible Rosa26 CreERT. This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for LPS induced cytokine production and migration which appears to be a major contributor to the inflammatory response in vivo. Whereas MKK4 plays a significant but minor role in cytokine production in vivo.

scholarly journals Mitogen Kinase Kinase (MKK7) Controls Cytokine Production In Vitro and In Vivo in Mice

2021 ◽  
Vol 22 (17) ◽  
pp. 9364
Author(s):  
Amada D. Caliz ◽  
Hyung-Jin Yoo ◽  
Anastassiia Vertii ◽  
Ana C. Dolan ◽  
Cathy Tournier ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Cell Types ◽  
Minor Role ◽  
Cellular Processes ◽  
Mitogen Activated Protein ◽  
And Migration ◽  
Jnk Activation

Mitogen kinase kinase 4 (MKK4) and mitogen kinase kinase 7 (MKK7) are members of the MAP2K family that can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both c-Jun N-terminal kinase (JNK) and p38 MAPK, while MKK7 has been reported to activate only JNK in response to different stimuli. The stimuli, as well as the cell type determine which MAP2K member will mediate a given response. In various cell types, MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have also implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK4 and MKK7 contribute to innate immune responses in macrophages or during inflammation in vivo. To address this question and to elucidate the role of MKK4 and MKK7 in macrophage and in vivo, we developed MKK4- and MKK7-deficient mouse models with tamoxifen-inducible Rosa26 CreERT. This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for lipopolysaccharide (LPS)-induced cytokine production, M1 polarization, and migration, which appear to be a major contributor to the inflammatory response in vivo. Conversely, MKK4 plays a significant, but minor role in cytokine production in vivo.

Knockout of Ajuba Attenuates the Growth and Migration of Hepatocellular Carcinoma Cells

2020 ◽  
Vol 160 (11-12) ◽  
pp. 650-658
Author(s):  
Yichen Le ◽  
Yi He ◽  
Meirong Bai ◽  
Ying Wang ◽  
Jiaxue Wu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Growth ◽  
Cancer Progression ◽  
Normal Liver ◽  
Cell Growth And Migration ◽  
And Migration ◽  
Hcc Cells

Ajuba has been found to be mutated or aberrantly regulated in several human cancers and plays important roles in cancer progression via different signaling pathways. However, little is known about the role of Ajuba in hepatocellular carcinoma (HCC). Here, we found an upregulation of Ajuba expression in HCC tissues compared with normal liver tissues, while a poor prognosis was observed in HCC patients with high Ajuba expression. Knockout of Ajuba in HCC cells inhibited cell growth in vitro and in vivo, suppressed cell migration, and enhanced the cell apoptosis under stress. Moreover, re-expression of Ajuba in Ajuba-deficient cells could restore the phenotype of Ajuba-deficient cells. In conclusion, these results indicate that Ajuba is upregulated in HCC and promotes cell growth and migration of HCC cells, suggesting that Ajuba could possibly be a new target for HCC diagnosis and treatment.

miR-125b enhances metastasis and progression of cancer via the TXNIP and HIF1α pathway in pancreatic cancer

2021 ◽  
pp. 1-12
Author(s):  
Pengli Wang ◽  
Dan Zheng ◽  
Hongyang Qi ◽  
Qi Gao
Keyword(s):  
Pancreatic Cancer ◽  
Hypoxia Inducible Factor ◽  
Immunofluorescence Assay ◽  
Luciferase Assay ◽  
Interacting Protein ◽  
Over Expression ◽  
Thioredoxin Interacting Protein ◽  
Cellular Processes ◽  
And Migration

BACKGROUND: MicroRNAs (miRNAs) play potential role in the development of various types of cancer conditions including pancreatic cancer (PC) targeting several cellular processes. Present study was aimed to evaluate function of miR-125b and the mechanism involved in PC. METHODS: Cell migration, MTT and BrdU study was done to establish the migration capability, cell viability and cell proliferation respectively. Binding sites for miR-125b were recognized by luciferase assay, expression of protein by western blot and immunofluorescence assay. In vivo study was done by BALB/c nude xenograft mice for evaluating the function of miR-125b. RESULTS: The study showed that expression of miR-125b was elevated in PC cells and tissues, and was correlated to proliferation and migration of cells. Also, over-expression of miR-125b encouraged migration, metastasis and proliferation of BxPC-3 cells, the suppression reversed it. We also noticed that thioredoxin-interacting protein (TXNIP) was the potential target of miR-125b. The outcomes also suggested that miR-125b governed the expression of TXNIP inversely via directly attaching to the 3′-UTR activating hypoxia-inducible factor 1α (HIF1α). Looking into the relation between HIF1α and TXNIP, we discovered that TXNIP caused the degradation and export of HIF1α by making a complex with it. CONCLUSION: The miR-125b-TXNIP-HIF1α pathway may serve useful strategy for diagnosing and treating PC.

scholarly journals Progression and Differentiation of Alveolar Rhabdomyosarcoma Is Regulated by PAX7 Transcription Factor—Significance of Tumor Subclones

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1870
Author(s):  
Klaudia Skrzypek ◽  
Grażyna Adamek ◽  
Marta Kot ◽  
Bogna Badyra ◽  
Marcin Majka
Keyword(s):  
Transcription Factor ◽  
Cell Lines ◽  
Migration Activity ◽  
Id Proteins ◽  
Rh30 Cell ◽  
Str Profile ◽  
And Migration

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.

scholarly journals The first “Slit” is the deepest: the secret to a hollow heart

2008 ◽  
Vol 182 (2) ◽  
pp. 221-223 ◽  
Author(s):  
Iiro Taneli Helenius ◽  
Greg J. Beitel
Keyword(s):  
Cell Shape ◽  
Vascular System ◽  
Hollow Heart ◽  
Autocrine Signaling ◽  
Lumen Formation ◽  
Membrane Surfaces ◽  
Vascular Morphogenesis ◽  
Cell Biol ◽  
Shape Changes

Tubular organs are essential for life, but lumen formation in nonepithelial tissues such as the vascular system or heart is poorly understood. Two studies in this issue (Medioni, C., M. Astier, M. Zmojdzian, K. Jagla, and M. Sémériva. 2008. J. Cell Biol. 182:249–261; Santiago-Martínez, E., N.H. Soplop, R. Patel, and S.G. Kramer. 2008. J. Cell Biol. 182:241–248) reveal unexpected roles for the Slit–Robo signaling system during Drosophila melanogaster heart morphogenesis. In cardioblasts, Slit and Robo modulate the cell shape changes and domains of E-cadherin–based adhesion that drive lumen formation. Furthermore, in contrast to the well-known paracrine role of Slit and Robo in guiding cell migrations, here Slit and Robo may act by autocrine signaling. In addition, the two groups demonstrate that heart lumen formation is even more distinct from typical epithelial tubulogenesis mechanisms because the heart lumen is bounded by membrane surfaces that have basal rather than apical attributes. As the D. melanogaster cardioblasts are thought to have significant evolutionary similarity to vertebrate endothelial and cardiac lineages, these findings are likely to provide insights into mechanisms of vertebrate heart and vascular morphogenesis.

scholarly journals Myosin-dependent remodeling of adherens junctions protects junctions from Snail-dependent disassembly

2016 ◽  
Vol 212 (2) ◽  
pp. 219-229 ◽  
Author(s):  
Mo Weng ◽  
Eric Wieschaus
Keyword(s):  
Cell Shape ◽  
Adherens Junctions ◽  
Myosin Ii ◽  
Cell Junctions ◽  
Snail Expression ◽  
Quantitative Image ◽  
Early Expression ◽  
Temporally Correlated ◽  
Shape Changes

Although Snail is essential for disassembly of adherens junctions during epithelial–mesenchymal transitions (EMTs), loss of adherens junctions in Drosophila melanogaster gastrula is delayed until mesoderm is internalized, despite the early expression of Snail in that primordium. By combining live imaging and quantitative image analysis, we track the behavior of E-cadherin–rich junction clusters, demonstrating that in the early stages of gastrulation most subapical clusters in mesoderm not only persist, but move apically and enhance in density and total intensity. All three phenomena depend on myosin II and are temporally correlated with the pulses of actomyosin accumulation that drive initial cell shape changes during gastrulation. When contractile myosin is absent, the normal Snail expression in mesoderm, or ectopic Snail expression in ectoderm, is sufficient to drive early disassembly of junctions. In both cases, junctional disassembly can be blocked by simultaneous induction of myosin contractility. Our findings provide in vivo evidence for mechanosensitivity of cell–cell junctions and imply that myosin-mediated tension can prevent Snail-driven EMT.

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