scholarly journals Plant immune and growth receptors share common signalling components but localise to distinct plasma membrane nanodomains

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Christoph A Bücherl ◽  
Iris K Jarsch ◽  
Christian Schudoma ◽  
Cécile Segonzac ◽  
Malick Mbengue ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Protein Complexes ◽  
Spatial Separation ◽  
Single Particle Tracking ◽  
Surface Receptors ◽  
Receptor Complexes ◽  
Receptor Kinases ◽  
Multicellular Organisms

Cell surface receptors govern a multitude of signalling pathways in multicellular organisms. In plants, prominent examples are the receptor kinases FLS2 and BRI1, which activate immunity and steroid-mediated growth, respectively. Intriguingly, despite inducing distinct signalling outputs, both receptors employ common downstream signalling components, which exist in plasma membrane (PM)-localised protein complexes. An important question is thus how these receptor complexes maintain signalling specificity. Live-cell imaging revealed that FLS2 and BRI1 form PM nanoclusters. Using single-particle tracking we could discriminate both cluster populations and we observed spatiotemporal separation between immune and growth signalling platforms. This finding was confirmed by visualising FLS2 and BRI1 within distinct PM nanodomains marked by specific remorin proteins and differential co-localisation with the cytoskeleton. Our results thus suggest that signalling specificity between these pathways may be explained by the spatial separation of FLS2 and BRI1 with their associated signalling components within dedicated PM nanodomains.

scholarly journals Conformational specificity of opioid receptors is determined by subcellular location irrespective of agonist

2021 ◽  
Author(s):  
Stephanie E. Crilly ◽  
Wooree Ko ◽  
Zara Y. Weinberg ◽  
Manojkumar A. Puthenveedu
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Opioid Receptors ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Subcellular Location ◽  
Unanswered Question ◽  
Receptor Coupling ◽  
Δ Opioid Receptor ◽  
G Protein Coupled

AbstractThe prevailing model for the variety in drug responses is that they stabilize distinct active states of their G protein-coupled receptor (GPCR) targets, allowing coupling to different effectors. However, whether the same ligand can produce different GPCR active states based on the environment of receptors in cells is a fundamental unanswered question. Here we address this question using live cell imaging of conformational biosensors that read out distinct active conformations of the δ-opioid receptor (DOR), a physiologically relevant GPCR localized to Golgi and the surface in neurons. We show that, although Golgi and surface pools of DOR regulated cAMP, the two pools engaged distinct conformational biosensors in response to the same ligand. Further, DOR recruited arrestin on the plasma membrane but not the Golgi. Our results suggest that the same agonist drives different conformations of a GPCR at different locations, allowing receptor coupling to distinct effectors at different locations.

scholarly journals EB1 binding restricts STIM1 translocation to ER–PM junctions and regulates store-operated Ca2+ entry

2018 ◽  
Vol 217 (6) ◽  
pp. 2047-2058 ◽  
Author(s):  
Chi-Lun Chang ◽  
Yu-Ju Chen ◽  
Carlo Giovanni Quintanilla ◽  
Ting-Sung Hsieh ◽  
Jen Liou
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Cellular Functions ◽  
Binding Ability ◽  
Trapping Mechanism ◽  
Spatiotemporal Regulation

The endoplasmic reticulum (ER) Ca2+ sensor STIM1 forms oligomers and translocates to ER–plasma membrane (PM) junctions to activate store-operated Ca2+ entry (SOCE) after ER Ca2+ depletion. STIM1 also interacts with EB1 and dynamically tracks microtubule (MT) plus ends. Nevertheless, the role of STIM1–EB1 interaction in regulating SOCE remains unresolved. Using live-cell imaging combined with a synthetic construct approach, we found that EB1 binding constitutes a trapping mechanism restricting STIM1 targeting to ER–PM junctions. We further showed that STIM1 oligomers retain EB1 binding ability in ER Ca2+-depleted cells. By trapping STIM1 molecules at dynamic contacts between the ER and MT plus ends, EB1 binding delayed STIM1 translocation to ER–PM junctions during ER Ca2+ depletion and prevented excess SOCE and ER Ca2+ overload. Our study suggests that STIM1–EB1 interaction shapes the kinetics and amplitude of local SOCE in cellular regions with growing MTs and contributes to spatiotemporal regulation of Ca2+ signaling crucial for cellular functions and homeostasis.

Lipid order and molecular assemblies in the plasma membrane of eukaryotic cells

2009 ◽  
Vol 37 (5) ◽  
pp. 1056-1060 ◽  
Author(s):  
Marek Cebecauer ◽  
Dylan M. Owen ◽  
Anna Markiewicz ◽  
Anthony I. Magee
Keyword(s):  
Plasma Membrane ◽  
Physical Properties ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Eukaryotic Cells ◽  
Dynamic Nature ◽  
Membrane Components ◽  
Technological Improvements

Multimolecular assemblies on the plasma membrane exhibit dynamic nature and are often generated during the activation of eukaryotic cells. The role of lipids and their physical properties in helping to control the existence of these structures is discussed. Technological improvements for live cell imaging of membrane components are also reviewed.

scholarly journals Lysosome Mobility Probed with Live Cell Imaging and Single Particle Tracking

2013 ◽  
Vol 104 (2) ◽  
pp. 651a
Author(s):  
Debjyoti Bandyopadhyay ◽  
Youngeun J. Kim ◽  
Jairo Zapata ◽  
Christine K. Payne
Keyword(s):  
Particle Tracking ◽  
Single Particle ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Single Particle Tracking ◽  
Live Cell

scholarly journals EB1 binding provides a diffusion trap mechanism regulating STIM1 localization and Ca2+ signaling

2017 ◽  
Author(s):  
Chi-Lun Chang ◽  
Yu-Ju Chen ◽  
Jen Liou
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Time Lapse ◽  
Cellular Functions ◽  
Binding Ability ◽  
Spatiotemporal Regulation ◽  
Time Lapse Imaging

AbstractThe endoplasmic reticulum (ER) Ca2+ sensor STIM1 forms oligomers and translocates to ER-plasma membrane (PM) junctions to activate store-operated Ca2+ entry (SOCE) following ER Ca2+ depletion. STIM1 also directly interacts with end binding protein 1 (EB1) at microtubule (MT) plus-ends and resembles comet-like structures during time-lapse imaging. Nevertheless, the role of STIM1-EB1 interaction in regulating SOCE remains unresolved. Using live-cell imaging combined with pharmacological perturbation and a reconstitution approach, we revealed that EB1 binding constitutes a diffusion trap mechanism restricting STIM1 targeting to ER-PM junctions. We further showed that STIM1 oligomers retain EB1 binding ability in ER Ca2+-depleted cells. EB1 binding delayed the translocation of STIM1 oligomers to ER-PM junctions and recaptured STIM1 to prevent excess SOCE and ER Ca2+ overload. Thus, the counterbalance of EB1 binding and PM targeting of STIM1 shapes the kinetics and amplitude of local SOCE in regions with growing MTs, and contributes to precise spatiotemporal regulation of Ca2+ signaling crucial for cellular functions and homeostasis.SummarySTIM1 activates store-operated Ca2+ entry (SOCE) by translocating to endoplasmic reticulum-plasma membrane junctions. Chang et al. revealed that STIM1 localization and SOCE are regulated by a diffusion trap mechanism mediated by STIM1 binding to EB1 at growing microtubule ends.

scholarly journals FERONIA regulates FLS2 plasma membrane nanoscale dynamics to modulate plant immune signaling

2020 ◽  
Author(s):  
Julien Gronnier ◽  
Christina M. Franck ◽  
Martin Stegmann ◽  
Thomas A. DeFalco ◽  
Alicia Abarca Cifuentes ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Complex Formation ◽  
Cell Surface ◽  
Single Particle Tracking ◽  
Receptor Kinase ◽  
Leucine Rich Repeat ◽  
Immune Signaling ◽  
Receptor Complexes ◽  
Nanoscale Dynamics

ABSTRACTCell surface receptors survey and relay information to ensure the development and survival of multicellular organisms. In the model plant Arabidopsis thaliana, the Catharanthus roseus RLK1-like receptor kinase FERONIA (FER) regulates myriad of biological processes to coordinate development, growth and responses to the environment. We recently showed that FER positively regulates immune signaling by controlling the ligand-induced complex formation between the leucine-rich repeat receptor kinase (LRR-RK) FLAGELLIN SENSING 2 (FLS2) and its co-receptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1/SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3 (BAK1/SERK3). In this context, FER function is inhibited by binding of its peptide ligand RAPID ALKALINIZATION FACTOR 23 (RALF23). However, the mechanisms by which FER regulates FLS2-BAK1 complex formation remain unclear. Here, we show that FER-dependent regulation of immune signaling is independent of its kinase activity, indicating that FER rather plays a structural role. FER has been proposed to bind directly to the plant cell wall, but we found that a FER mutant unable to bind pectin is still functional in regulating immune signaling. Instead, FER- and cell wall-associated LEUCINE RICH REPEAT-EXTENSIN proteins are required for this regulation. Using high-resolution live-imaging and single-particle tracking, we observed that FER regulates FLS2 plasma membrane nanoscale dynamics, which may explain its role in controlling ligand-induced FLS2-BAK1 association. We propose that FER acts as an anchoring point connecting cell wall and plasma membrane nano-environments to enable the nucleation of pre-formed receptor/co-receptor complexes at the cell surface.

scholarly journals Live‐cell imaging of octaarginine‐modified polymer dots via single particle tracking

2019 ◽  
Vol 52 (2) ◽  
pp. e12556 ◽  
Author(s):  
Yao Luo ◽  
Yuping Han ◽  
Xingjie Hu ◽  
Min Yin ◽  
Changfeng Wu ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Single Particle ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Single Particle Tracking ◽  
Live Cell ◽  
Modified Polymer ◽  
Polymer Dots

scholarly journals Sphingomyelin is sorted at the trans Golgi network into a distinct class of secretory vesicle

2016 ◽  
Vol 113 (24) ◽  
pp. 6677-6682 ◽  
Author(s):  
Yongqiang Deng ◽  
Felix E. Rivera-Molina ◽  
Derek K. Toomre ◽  
Christopher G. Burd
Keyword(s):  
Plasma Membrane ◽  
Intracellular Trafficking ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Secretory Vesicle ◽  
Secretory Protein ◽  
Secretory Vesicles ◽  
Distinct Class ◽  
Equinatoxin Ii ◽  
Golgi Network

One of the principal functions of the trans Golgi network (TGN) is the sorting of proteins into distinct vesicular transport carriers that mediate secretion and interorganelle trafficking. Are lipids also sorted into distinct TGN-derived carriers? The Golgi is the principal site of the synthesis of sphingomyelin (SM), an abundant sphingolipid that is transported. To address the specificity of SM transport to the plasma membrane, we engineered a natural SM-binding pore-forming toxin, equinatoxin II (Eqt), into a nontoxic reporter termed Eqt-SM and used it to monitor intracellular trafficking of SM. Using quantitative live cell imaging, we found that Eqt-SM is enriched in a subset of TGN-derived secretory vesicles that are also enriched in a glycophosphatidylinositol-anchored protein. In contrast, an integral membrane secretory protein (CD8α) is not enriched in these carriers. Our results demonstrate the sorting of native SM at the TGN and its transport to the plasma membrane by specific carriers.

scholarly journals Distinct acto/myosin-I structures associate with endocytic profiles at the plasma membrane

2008 ◽  
Vol 180 (6) ◽  
pp. 1219-1232 ◽  
Author(s):  
Fatima-Zahra Idrissi ◽  
Helga Grötsch ◽  
Isabel M. Fernández-Golbano ◽  
Cristina Presciatto-Baschong ◽  
Howard Riezman ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Immunoelectron Microscopy ◽  
Live Cell Imaging ◽  
Actin Polymerization ◽  
Cell Imaging ◽  
Live Cell ◽  
Endocytic Vesicle ◽  
Myosin I ◽  
Initial Membrane ◽  
Membrane Bending

Endocytosis in yeast requires actin and clathrin. Live cell imaging has previously shown that massive actin polymerization occurs concomitant with a slow 200-nm inward movement of the endocytic coat (Kaksonen, M., Y. Sun, and D.G. Drubin. 2003. Cell. 115:475–487). However, the nature of the primary endocytic profile in yeast and how clathrin and actin cooperate to generate an endocytic vesicle is unknown. In this study, we analyze the distribution of nine different proteins involved in endocytic uptake along plasma membrane invaginations using immunoelectron microscopy. We find that the primary endocytic profiles are tubular invaginations of up to 50 nm in diameter and 180 nm in length, which accumulate the endocytic coat components at the tip. Interestingly, significant actin labeling is only observed on invaginations longer than 50 nm, suggesting that initial membrane bending occurs before initiation of the slow inward movement. We also find that in the longest profiles, actin and the myosin-I Myo5p form two distinct structures that might be implicated in vesicle fission.

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