scholarly journals A novel localization based biosensor, SEDAR, visualizes spatio-temporal dynamics of activated Ras in endogenous Drosophila tissues

2018 ◽  
Author(s):  
Rishita Changede

AbstractChemokine signaling via growth factor receptor tyrosine kinases (RTKs) regulates development, differentiation, growth and disease implying that it is involved in a myriad of cellular processes. A single RTK, for example the Epidermal Growth Factor Receptor (EGFR), is used repeatedly for a multitude of developmental programs. Quantitative differences in magnitude and duration of RTK signaling can bring about different signaling outcomes. Understanding this complex RTK signals requires real time visualization of the signal. To visualize spatio-temporal signaling dynamics, a biosensor called SEnsitive Detection of Activated Ras (SEDAR) was developed. It is a localization-based sensor that binds to activated Ras directly downstream of the endogenous activated RTKs. This binding was reversible and SEDAR expression did not cause any detectable perturbation of the endogenous signal. Using SEDAR, endogenous guidance signaling was visualized during RTK mediated chemotaxis of border cells in Drosophila ovary. SEDAR localized to both the leading and rear end of the cluster but polarized at the leading edge of the cluster. Perturbation of RTKs that led to delays in forward migration of the cluster correlated with loss of SEDAR polarization in the cluster. Gliding or tumbling behavior of border cells was a directly related to the high or low magnitude of SEDAR polarization respectively, in the leading cell showing that signal polarization at the plasma membrane provided information for the migratory behavior. Further, SEDAR localization to the plasma membrane detected EGFR mediated signaling in five distinct developmental contexts. Hence SEDAR, a novel biosensor could be used as a valuable tool to study the dynamics of endogenous Ras activation in real time downstream of RTKs, in three-dimensional tissues, at an unprecedented spatial and temporal resolution.

2001 ◽  
Vol 153 (3) ◽  
pp. 599-612 ◽  
Author(s):  
Miho Matsuda ◽  
Hugh F. Paterson ◽  
Rosie Rodriguez ◽  
Amanda C. Fensome ◽  
Moira V. Ellis ◽  
...  

The translocation of fluorescently tagged PLCγ and requirements for this process in cells stimulated with EGF were analyzed using real time fluorescence microscopy applied for the first time to monitor growth factor receptor–effector interactions. The translocation of PLCγ to the plasma membrane required the functional Src homology 2 domains and was not affected by mutations in the pleckstrin homology domain or inhibition of phosphatidylinositol (PI) 3-kinase. An array of domains specific for PLCγ isoforms was sufficient for this translocation. The dynamics of translocation to the plasma membrane and redistribution of PLCγ, relative to localization of the EGF receptor and PI 4,5-biphosphate (PI 4,5-P2), were shown. Colocalization with the receptor was observed in the plasma membrane and in membrane ruffles where PI 4,5-P2 substrate could also be visualized. At later times, internalization of PLCγ, which could lead to separation from the substrate, was observed. The data support a direct binding of PLCγ to the receptor as the main site of the plasma membrane recruitment. The presence of PLCγ in membrane structures and its access to the substrate appear to be transient and are followed by a rapid incorporation into intracellular vesicles, leading to downregulation of the PLC activity.


2011 ◽  
Vol 192 (3) ◽  
pp. 513-524 ◽  
Author(s):  
Minna Poukkula ◽  
Adam Cliffe ◽  
Rishita Changede ◽  
Pernille Rørth

Border cells perform a collective, invasive, and directed migration during Drosophila melanogaster oogenesis. Two receptor tyrosine kinases (RTKs), the platelet-derived growth factor/vascular endothelial growth factor–related receptor (PVR) and the epidermal growth factor receptor (EGFR), are important for reading guidance cues, but how these cues steer migration is not well understood. During collective migration, front, back, and side extensions dynamically project from individual cells within the group. We find that guidance input from both RTKs affects the presence and size of these extensions, primarily by favoring the persistence of front extensions. Guidance cues also control the productivity of extensions, specifically rendering back extensions nonproductive. Early and late phases of border cell migration differ in efficiency of forward cluster movement, although motility of individual cells appears constant. This is caused by differences in behavioral effects of the RTKs: PVR dominantly induces large persistent front extensions and efficient streamlined group movement, whereas EGFR does not. Thus, guidance receptors steer movement of this cell group by differentially affecting multiple migration-related features.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arndt Rohwedder ◽  
Sabine Knipp ◽  
Lee D. Roberts ◽  
John E. Ladbury

AbstractReceptor tyrosine kinases (RTKs) are highly regulated, single pass transmembrane proteins, fundamental to cellular function and survival. Aberrancies in regulation lead to corruption of signal transduction and a range of pathological outcomes. Although control mechanisms associated with the receptors and their ligands are well understood, little is known with respect to the impact of lipid/lipid and lipid/protein interactions in the proximal plasma membrane environment. Given that the transmembrane regions of RTKs change in response to extracellular ligand binding, the lipid interactions have important consequences in influencing signal transduction. Fibroblast growth factor receptor 2 (FGFR2) is a highly regulated RTK, including under basal conditions. Binding of the adaptor protein, growth factor receptor-bound protein 2 (GRB2) to FGFR2 prevents full activation and recruitment of downstream signalling effector proteins in the absence of extracellular stimulation. Here we demonstrate that the FGFR2-GRB2 complex is sustained in a defined lipid environment. Dissociation of GRB2 from this complex due to ligand binding, or reduced GRB2 expression, facilitates the dispersion of FGFR2 into detergent-resistant membrane (DRM) micro-domains. This modification of the plasma membrane proximal to FGFR2 provides a further regulatory checkpoint which controls receptor degradation, recycling and recruitment of intracellular signalling proteins.


2020 ◽  
Vol 17 (5) ◽  
pp. 585-615 ◽  
Author(s):  
Nikhil S. Sakle ◽  
Shweta A. More ◽  
Sachin A. Dhawale ◽  
Santosh N. Mokale

Background: Cancer is a complex disease involving genetic and epigenetic alteration that allows cells to escape normal homeostasis. Kinases play a crucial role in signaling pathways that regulate cell functions. Deregulation of kinases leads to a variety of pathological changes, activating cancer cell proliferation and metastases. The molecular mechanism of cancer is complex and the dysregulation of tyrosine kinases like Anaplastic Lymphoma Kinase (ALK), Bcr-Abl (Fusion gene found in patient with Chronic Myelogenous Leukemia (CML), JAK (Janus Activated Kinase), Src Family Kinases (SFKs), ALK (Anaplastic lymphoma Kinase), c-MET (Mesenchymal- Epithelial Transition), EGFR (Epidermal Growth Factor receptor), PDGFR (Platelet-Derived Growth Factor Receptor), RET (Rearranged during Transfection) and VEGFR (Vascular Endothelial Growth Factor Receptor) plays major role in the process of carcinogenesis. Recently, kinase inhibitors have overcome many problems of traditional cancer chemotherapy as they effectively separate out normal, non-cancer cells as well as rapidly multiplying cancer cells. Methods: Electronic databases were searched to explore the small molecule tyrosine kinases by polyphenols with the help of docking study (Glide-7.6 program interfaced with Maestro-v11.3 of Schrödinger 2017) to show the binding energies of polyphenols inhibitor with different tyrosine kinases in order to differentiate between the targets. Results: From the literature survey, it was observed that the number of polyphenols derived from natural sources alters the expression and signaling cascade of tyrosine kinase in various tumor models. Therefore, the development of polyphenols as a tyrosine kinase inhibitor against targeted proteins is regarded as an upcoming trend for chemoprevention. Conclusion: In this review, we have discussed the role of polyphenols as chemoreceptive which will help in future for the development and discovery of novel semisynthetic anticancer agents coupled with polyphenols.


Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 184
Author(s):  
Kalpana K. Bhanumathy ◽  
Amrutha Balagopal ◽  
Frederick S. Vizeacoumar ◽  
Franco J. Vizeacoumar ◽  
Andrew Freywald ◽  
...  

Protein kinases constitute a large group of enzymes catalysing protein phosphorylation and controlling multiple signalling events. The human protein kinase superfamily consists of 518 members and represents a complicated system with intricate internal and external interactions. Protein kinases are classified into two main families based on the ability to phosphorylate either tyrosine or serine and threonine residues. Among the 90 tyrosine kinase genes, 58 are receptor types classified into 20 groups and 32 are of the nonreceptor types distributed into 10 groups. Tyrosine kinases execute their biological functions by controlling a variety of cellular responses, such as cell division, metabolism, migration, cell–cell and cell matrix adhesion, cell survival and apoptosis. Over the last 30 years, a major focus of research has been directed towards cancer-associated tyrosine kinases owing to their critical contributions to the development and aggressiveness of human malignancies through the pathological effects on cell behaviour. Leukaemia represents a heterogeneous group of haematological malignancies, characterised by an uncontrolled proliferation of undifferentiated hematopoietic cells or leukaemia blasts, mostly derived from bone marrow. They are usually classified as chronic or acute, depending on the rates of their progression, as well as myeloid or lymphoblastic, according to the type of blood cells involved. Overall, these malignancies are relatively common amongst both children and adults. In malignant haematopoiesis, multiple tyrosine kinases of both receptor and nonreceptor types, including AXL receptor tyrosine kinase (AXL), Discoidin domain receptor 1 (DDR1), Vascular endothelial growth factor receptor (VEGFR), Fibroblast growth factor receptor (FGFR), Mesenchymal–epithelial transition factor (MET), proto-oncogene c-Src (SRC), Spleen tyrosine kinase (SYK) and pro-oncogenic Abelson tyrosine-protein kinase 1 (ABL1) mutants, are implicated in the pathogenesis and drug resistance of practically all types of leukaemia. The role of ABL1 kinase mutants and their therapeutic inhibitors have been extensively analysed in scientific literature, and therefore, in this review, we provide insights into the impact and mechanism of action of other tyrosine kinases involved in the development and progression of human leukaemia and discuss the currently available and emerging treatment options based on targeting these molecules.


2000 ◽  
Vol 11 (11) ◽  
pp. 3873-3883 ◽  
Author(s):  
Maryse Bailly ◽  
Jeffrey Wyckoff ◽  
Boumediene Bouzahzah ◽  
Ross Hammerman ◽  
Vonetta Sylvestre ◽  
...  

To determine the distribution of the epidermal growth factor (EGF) receptor (EGFR) on the surface of cells responding to EGF as a chemoattractant, an EGFR-green fluorescent protein chimera was expressed in the MTLn3 mammary carcinoma cell line. The chimera was functional and easily visualized on the cell surface. In contrast to other studies indicating that the EGFR might be localized to certain regions of the plasma membrane, we found that the chimera is homogeneously distributed on the plasma membrane and becomes most concentrated in vesicles after endocytosis. In spatial gradients of EGF, endocytosed receptor accumulates on the upgradient side of the cell. Visualization of the binding of fluorescent EGF to cells reveals that the affinity properties of the receptor, together with its expression level on cells, can provide an initial amplification step in spatial gradient sensing.


1996 ◽  
Vol 135 (6) ◽  
pp. 1633-1642 ◽  
Author(s):  
S Miyamoto ◽  
H Teramoto ◽  
J S Gutkind ◽  
K M Yamada

Integrins mediate cell adhesion, migration, and a variety of signal transduction events. These integrin actions can overlap or even synergize with those of growth factors. We examined for mechanisms of collaboration or synergy between integrins and growth factors involving MAP kinases, which regulate many cellular functions. In cooperation with integrins, the growth factors EGF, PDGF-BB, and basic FGF each produced a marked, transient activation of the ERK (extracellular signal-regulated kinase) class of MAP kinase, but only if the integrins were both aggregated and occupied by ligand. Transmembrane accumulation of total tyrosine-phosphorylated proteins, as well as nonsynergistic MAP kinase activation, could be induced by simple integrin aggregation, whereas enhanced transient accumulation of the EGF-receptor substrate eps8 required integrin aggregation and occupancy, as well as EGF treatment. Each type of growth factor receptor was itself induced to aggregate transiently by integrin ligand-coated beads in a process requiring both aggregation and occupancy of integrin receptors, but not the presence of growth factor ligand. Synergism was also observed between integrins and growth factors for triggering tyrosine phosphorylation of EGF, PDGF, and FGF receptors. This collaborative response also required both integrin aggregation and occupancy. These studies identify mechanisms in the signal transduction response to integrins and growth factors that require various combinations of integrin aggregation and ligands for integrin or growth factor receptors, providing opportunities for collaboration between these major regulatory systems.


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