scholarly journals ADF/cofilin promotes invadopodial membrane recycling during cell invasion in vivo

2014 ◽  
Vol 204 (7) ◽  
pp. 1209-1218 ◽  
Author(s):  
Elliott J. Hagedorn ◽  
Laura C. Kelley ◽  
Kaleb M. Naegeli ◽  
Zheng Wang ◽  
Qiuyi Chi ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Cell Invasion ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Actin Dynamics ◽  
Membrane Structures ◽  
Tumor Dissemination ◽  
Anchor Cell ◽  
Dynamic Structures

Invadopodia are protrusive, F-actin–driven membrane structures that are thought to mediate basement membrane transmigration during development and tumor dissemination. An understanding of the mechanisms regulating invadopodia has been hindered by the difficulty of examining these dynamic structures in native environments. Using an RNAi screen and live-cell imaging of anchor cell (AC) invasion in Caenorhabditis elegans, we have identified UNC-60A (ADF/cofilin) as an essential regulator of invadopodia. UNC-60A localizes to AC invadopodia, and its loss resulted in a dramatic slowing of F-actin dynamics and an inability to breach basement membrane. Optical highlighting indicated that UNC-60A disassembles actin filaments at invadopodia. Surprisingly, loss of unc-60a led to the accumulation of invadopodial membrane and associated components within the endolysosomal compartment. Photobleaching experiments revealed that during normal invasion the invadopodial membrane undergoes rapid recycling through the endolysosome. Together, these results identify the invadopodial membrane as a specialized compartment whose recycling to form dynamic, functional invadopodia is dependent on localized F-actin disassembly by ADF/cofilin.

scholarly journals Interactions of WASp, myosin-I, and verprolin with Arp2/3 complex during actin patch assembly in fission yeast

2005 ◽  
Vol 170 (4) ◽  
pp. 637-648 ◽  
Author(s):  
Vladimir Sirotkin ◽  
Christopher C. Beltzner ◽  
Jean-Baptiste Marchand ◽  
Thomas D. Pollard
Keyword(s):  
Fission Yeast ◽  
Live Cell Imaging ◽  
Biochemical Analysis ◽  
Cell Imaging ◽  
Activator Proteins ◽  
Myosin I ◽  
Class 1 ◽  
Dynamic Structures ◽  
Actin Patch

Yeast actin patches are dynamic structures that form at the sites of cell growth and are thought to play a role in endocytosis. We used biochemical analysis and live cell imaging to investigate actin patch assembly in fission yeast Schizosaccharomyces pombe. Patch assembly proceeds via two parallel pathways: one dependent on WASp Wsp1p and verprolin Vrp1p converges with another dependent on class 1 myosin Myo1p to activate the actin-related protein 2/3 (Arp2/3) complex. Wsp1p activates Arp2/3 complex via a conventional mechanism, resulting in branched filaments. Myo1p is a weaker Arp2/3 complex activator that makes unstable branches and is enhanced by verprolin. During patch assembly in vivo, Wsp1p and Vrp1p arrive first independent of Myo1p. Arp2/3 complex associates with nascent activator patches over 6–9 s while remaining stationary. After reaching a maximum concentration, Arp2/3 complex patches move centripetally as activator proteins dissociate. Genetic dependencies of patch formation suggest that patch formation involves cross talk between Myo1p and Wsp1p/Vrp1p pathways.

scholarly journals UNC-6 (netrin) stabilizes oscillatory clustering of the UNC-40 (DCC) receptor to orient polarity

2014 ◽  
Vol 206 (5) ◽  
pp. 619-633 ◽  
Author(s):  
Zheng Wang ◽  
Lara M. Linden ◽  
Kaleb M. Naegeli ◽  
Joshua W. Ziel ◽  
Qiuyi Chi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Membrane ◽  
Cell Invasion ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Time Lapse ◽  
Oscillatory Behavior ◽  
Deleted In Colorectal Cancer ◽  
Family Protein ◽  
Anchor Cell

The receptor deleted in colorectal cancer (DCC) directs dynamic polarizing activities in animals toward its extracellular ligand netrin. How DCC polarizes toward netrin is poorly understood. By performing live-cell imaging of the DCC orthologue UNC-40 during anchor cell invasion in Caenorhabditis elegans, we have found that UNC-40 clusters, recruits F-actin effectors, and generates F-actin in the absence of UNC-6 (netrin). Time-lapse analyses revealed that UNC-40 clusters assemble, disassemble, and reform at periodic intervals in different regions of the cell membrane. This oscillatory behavior indicates that UNC-40 clusters through a mechanism involving interlinked positive (formation) and negative (disassembly) feedback. We show that endogenous UNC-6 and ectopically provided UNC-6 orient and stabilize UNC-40 clustering. Furthermore, the UNC-40–binding protein MADD-2 (a TRIM family protein) promotes ligand-independent clustering and robust UNC-40 polarization toward UNC-6. Together, our data suggest that UNC-6 (netrin) directs polarized responses by stabilizing UNC-40 clustering. We propose that ligand-independent UNC-40 clustering provides a robust and adaptable mechanism to polarize toward netrin.

CBIO-17. A NOVEL ROLE FOR ATR KINASE DETERMINES GLIOBLASTOMA TUMOUR CELL INVASION

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi30-vi30
Author(s):  
ross carruthers ◽  
Sarah Derby ◽  
Karen Strathdee ◽  
Anthony Chalmers ◽  
Jim Norman ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Invasion ◽  
Tumour Cell ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Tumour Cell Invasion ◽  
Atr Kinase

Abstract BACKGROUND: Widespread contamination of the brain with malignant cells is a predominant feature of glioblastoma (GBM) and fatal brainstem infiltration is frequently observed at autopsy. Whilst radiotherapy improves survival, irradiation increases GBM cell invasion, resulting in sublethal dose to cells migrating outside the irradiated volume. Tumour cell invasion should be a therapeutic priority if survival is to be improved. The responsible molecular mechanisms are key to improving outcomes but remain enigmatic. Ataxia telangiectasia and rad3-related (ATR) is a DNA damage response (DDR) kinase involved in DNA replication stress (RS) response and is an established therapeutic target for GBM. In this study we demonstrate a novel role for ATR kinase in facilitating malignant cell invasion. METHODS AND RESULTS: Invading margins of human GBM samples demonstrated increased pATR expression relative to core. Live cell imaging demonstrated a reduction in cell velocity following ATR inhibition (ATRi; VE822) or ATR siRNA, and a retraction defect was evident in vitro. Extensive cytoplasmic vacuolation occurred following ATRi or siRNA which were single walled structures on electron microscopy which could engulf high molecular weight dextran, suggesting blockade of macropinosome processing. Live cell imaging with GFP-integrin α5 and integrin recycling assays showed integrin sequestration within macropinosomes and reduced integrin internalisation respectively. Interrogation of a published ‘ATR interactome’ revealed ATR targets with functions in endocytic vesicle trafficking. Intravital in vivo imaging of murine xenograft tumours confirmed vacuolation and dextran uptake following ATRi, whilst a further study demonstrated reduced invading tumour cells following ATRi in intracranial xenografts. CONCLUSION: We demonstrate a novel role for ATR in facilitating macropinocytic vesicle trafficking and integrin internalisation. ATRi results in a profound motility defect in vitro and in vivo. ATR inhibitors are entering early phase trials as radiation sensitisers and we propose that therapeutic benefit will extend beyond DNA damage potentiation.

scholarly journals A Decade of Imaging Cellular Motility and Interaction Dynamics in the Immune System

Science ◽  
2012 ◽  
Vol 336 (6089) ◽  
pp. 1676-1681 ◽  
Author(s):  
Ronald N. Germain ◽  
Ellen A. Robey ◽  
Michael D. Cahalan
Keyword(s):  
Lymph Nodes ◽  
Live Cell Imaging ◽  
Quantitative Measurement ◽  
Cell Imaging ◽  
Plasma Cells ◽  
Effector T Cells ◽  
Cellular Interactions ◽  
Cellular Motility ◽  
Response Dynamics

To mount an immune response, lymphocytes must recirculate between the blood and lymph nodes, recognize antigens upon contact with specialized presenting cells, proliferate to expand a small number of clonally relevant lymphocytes, differentiate to antibody-producing plasma cells or effector T cells, exit from lymph nodes, migrate to tissues, and engage in host-protective activities. All of these processes involve motility and cellular interactions—events that were hidden from view until recently. Introduced to immunology by three papers in this journal in 2002, in vivo live-cell imaging studies are revealing the behavior of cells mediating adaptive and innate immunity in diverse tissue environments, providing quantitative measurement of cellular motility, interactions, and response dynamics. Here, we review themes emerging from such studies and speculate on the future of immunoimaging.

A new visible-light-excitable ICT-CHEF-mediated fluorescence ‘turn-on’ probe for the selective detection of Cd2+ in a mixed aqueous system with live-cell imaging

2015 ◽  
Vol 44 (12) ◽  
pp. 5763-5770 ◽  
Author(s):  
Shyamaprosad Goswami ◽  
Krishnendu Aich ◽  
Sangita Das ◽  
Chitrangada Das Mukhopadhyay ◽  
Deblina Sarkar ◽  
...  
Keyword(s):  
Visible Light ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Aqueous System ◽  
Live Cell ◽  
Selective Detection ◽  
Turn On ◽  
Fluorescence Turn On

A new quinoline based sensor was developed and applied for the selective detection of Cd2+ both in vitro and in vivo.

Live-Cell Imaging of F-Actin Dynamics During Fertilization in Arabidopsis thaliana

2017 ◽  
pp. 47-54 ◽  
Author(s):  
Daichi Susaki ◽  
Daisuke Maruyama ◽  
Ramesh Yelagandula ◽  
Frederic Berger ◽  
Tomokazu Kawashima
Keyword(s):  
Arabidopsis Thaliana ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Actin Dynamics

scholarly journals Regeneration of the neurogliovascular unit visualized in vivo by transcranial live-cell imaging

2020 ◽  
Vol 343 ◽  
pp. 108808 ◽  
Author(s):  
Margarita Arango-Lievano ◽  
Yann Dromard ◽  
Pierre Fontanaud ◽  
Chrystel Lafont ◽  
Patrice Mollard ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell

An aggregation-induced phosphorescence probe for calcium ion-specific detection and live-cell imaging in Arabidopsis thaliana

2019 ◽  
Vol 55 (33) ◽  
pp. 4841-4844 ◽  
Author(s):  
Guilin Chen ◽  
Zaicai Zhou ◽  
Hui Feng ◽  
Chenyan Zhang ◽  
Yifan Wang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Calcium Ion ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Molecular Probe ◽  
Specific Detection ◽  
Phosphorescence Probe

A molecular probe with aggregation-induced phosphorescence (AIP) properties for calcium ion-specific detection and imaging in vivo was designed.

scholarly journals Detection and Characterization of Protein Interactions In Vivo by a Simple Live-Cell Imaging Method

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62195 ◽  
Author(s):  
Oriol Gallego ◽  
Tanja Specht ◽  
Thorsten Brach ◽  
Arun Kumar ◽  
Anne-Claude Gavin ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Imaging Method
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