scholarly journals Characterization of neuronal synaptopodin reveals a myosin V-dependent mechanism of synaptopodin clustering at the post-synaptic sites

2019 ◽  
Author(s):  
Judit Gonzalez-Gallego ◽  
Anja Konietzny ◽  
Alberto Perez-Alvarez ◽  
Julia Baer ◽  
Urban Maier ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Pyramidal Neurons ◽  
Super Resolution ◽  
Myosin V ◽  
Interaction Partners ◽  
Spine Apparatus ◽  
Tight Association ◽  
Super Resolution Microscopy ◽  
Dependent Mechanism

The spine apparatus (SA) is an endoplasmic reticulum-related organelle which is present in a subset of dendritic spines in cortical and pyramidal neurons. The synaptopodin protein localizes between the stacks of the spine apparatus and is essential for the formation of this unique organelle. Although several studies have demonstrated the significance of the SA and synaptopodin in calcium homeostasis and plasticity of dendritic spines, it is still unclear what factors contribute to its stability at the synapse and whether the SA is locally formed or it is actively delivered to the spines. In this study we show that synaptopodin clusters are stable at their locations. We found no evidence of active microtubule-based transport for synaptopodin. Instead new clusters were emerging in the spines, which we interpret as the SA being assembled on-site. Furthermore, using super-resolution microscopy we show a tight association of synaptopodin with actin filaments. We identify the actin-based motor proteins myosin V and VI as novel interaction partners of synaptopodin and demonstrate that myosin V is important for the formation and/or maintenance of the SA.

scholarly journals Characterization of Plasma Membrane Ceramides by Super-Resolution Microscopy

2017 ◽  
Vol 56 (22) ◽  
pp. 6131-6135 ◽  
Author(s):  
Anne Burgert ◽  
Jan Schlegel ◽  
Jérôme Bécam ◽  
Sören Doose ◽  
Erhard Bieberich ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Super Resolution ◽  
Super Resolution Microscopy

scholarly journals Can Super-Resolution Microscopy Become a Standard Characterization Technique for Material Chemistry?

2021 ◽  
Author(s):  
Shikha Dhiman ◽  
Teodora Andrian ◽  
Beatriz Santiago ◽  
Marrit Tholen ◽  
Yuyang Wang ◽  
...  
Keyword(s):  
Super Resolution ◽  
Analytical Techniques ◽  
Material Chemistry ◽  
Characterization Technique ◽  
Super Resolution Microscopy ◽  
Synthesized Materials

The characterization of newly synthesized materials is a cornerstone of all chemistry and nanotechnology laboratories. For this purpose, a wide array of analytical techniques have been standardized and are used...

scholarly journals Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5

2021 ◽  
Author(s):  
Silvia Galiani ◽  
Katharina Reglinski ◽  
Pablo Carravilla ◽  
Aurelien Barbotin ◽  
Iztok Urbančič ◽  
...  
Keyword(s):  
Molecular Interactions ◽  
Super Resolution ◽  
Correlation Spectroscopy ◽  
Fluorescence Correlation ◽  
Interaction Dynamics ◽  
Diffusion Dynamics ◽  
Interaction Partners ◽  
Target Binding ◽  
Import Receptor

Measuring diffusion dynamics in living cells is essential for the understanding of molecular interactions. While various techniques have been used to explore such characteristics in the plasma membrane, this is less developed for measurements inside the cytosol. An example of cytosolic action is the import of proteins into peroxisomes, via the peroxisomal import receptor PEX5. Here, we combined advanced microscopy and spectroscopy techniques such as fluorescence correlation spectroscopy (FCS) and super-resolution STED microscopy to present a detailed characterization of the diffusion and interaction dynamics of PEX5. Among other features, we disclose a slow diffusion of PEX5, independent of aggregation or target binding, but associated with cytosolic interaction partners via its N-terminal domain. This sheds new light on the functionality of the receptor in the cytosol. Besides specific insights, our study highlights the potential of using complementary microscopy tools to decipher molecular interactions in the cytosol via studying their diffusion dynamics.

scholarly journals Synaptic anchoring of the endoplasmic reticulum depends on myosin V and caldendrin activity

2020 ◽  
Author(s):  
Anja Konietzny ◽  
Jasper Grendel ◽  
Nathalie Hertrich ◽  
Dick H. W. Dekkers ◽  
Jeroen A. A. Demmers ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Motor Function ◽  
Light Chain ◽  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Molecular Diversity ◽  
Fine Tuning ◽  
Excitatory Synapses ◽  
Myosin V ◽  
Spine Apparatus

AbstractExcitatory synapses of principal hippocampal neurons are frequently located on dendritic spines. The dynamic strengthening or weakening of individual inputs results in a great structural and molecular diversity of dendritic spines. Active spines with large Ca2+ transients are frequently invaded by a single protrusion from the endoplasmic reticulum (ER), which is dynamically transported into and out of spines by the actin-based motor myosin V. An increase in synaptic strength often correlates with stable anchoring of the ER, followed by the formation of the spine apparatus organelle. Here we show that synaptic ER stabilization depends on the interplay of two Ca2+-binding proteins: calmodulin serves as a light chain of myosin V and activates the motor function, whereas caldendrin acts as an inhibitor which transforms myosin into a stationary F-actin tether. Together, they provide a Ca2+-sensing module for fine-tuning myosin V activity and thereby regulate the formation of the spine apparatus in a subset of active dendritic spines.

scholarly journals Detyrosinated microtubules spatially constrain lysosomes facilitating lysosome–autophagosome fusion

2018 ◽  
Vol 218 (2) ◽  
pp. 632-643 ◽  
Author(s):  
Nitin Mohan ◽  
Elena M. Sorokina ◽  
Ione Vilanova Verdeny ◽  
Angel Sandoval Alvarez ◽  
Melike Lakadamyali
Keyword(s):  
Epithelial Cells ◽  
Functional Diversity ◽  
Super Resolution ◽  
Live Cell ◽  
Small Subset ◽  
Post Translational Modifications ◽  
Super Resolution Microscopy ◽  
Small Subpopulation ◽  
Dependent Mechanism

Microtubule post-translational modifications impart functional diversity to microtubules by affecting their dynamics, organization, and interaction with proteins. Using super-resolution microscopy, we show that only a small subpopulation of microtubules are detyrosinated in epithelial cells, while acetylated and tyrosinated microtubules comprise the majority of all microtubules. Surprisingly, lysosomes are enriched by approximately threefold on detyrosinated microtubules. Further, their motility on detyrosinated microtubules is impaired, showing shorter runs and more frequent and longer pauses. Lysosome enrichment is mediated through a kinesin-1–dependent mechanism, since knocking down this motor abolishes enrichment. Finally, correlative live-cell and super-resolution microscopy showed that lysosomes interact with autophagosomes on detyrosinated microtubules. Removal of detyrosinated microtubules or knockdown of kinesin-1 leads to a decrease in the percentage of autolysosomes, a fusion intermediate of autophagosomes and lysosomes. Taken together, our data reveal a new role of detyrosinated microtubules as hubs that spatially concentrate lysosomes on a small subset of microtubules and facilitate their interaction and fusion with autophagosomes to initiate autophagy.

scholarly journals Experimental characterization of 3D localization techniques for particle-tracking and super-resolution microscopy

2009 ◽  
Vol 17 (10) ◽  
pp. 8264 ◽  
Author(s):  
Michael J. Mlodzianoski ◽  
Manuel F. Juette ◽  
Glen L. Beane ◽  
Joerg Bewersdorf
Keyword(s):  
Particle Tracking ◽  
Super Resolution ◽  
Experimental Characterization ◽  
3D Localization ◽  
Super Resolution Microscopy

scholarly journals Characterization of Ire1 Interactions and Dynamics with Quantitative Super-Resolution Microscopy

2017 ◽  
Vol 112 (3) ◽  
pp. 148a
Author(s):  
Elizabeth M. Smith ◽  
Ragnar Stefansson ◽  
Maria Paz Ramirez Lopez ◽  
Elias M. Puchner
Keyword(s):  
Super Resolution ◽  
Super Resolution Microscopy

scholarly journals Caldendrin and myosin V regulate synaptic spine apparatus localization via ER stabilization in dendritic spines

2021 ◽  
Author(s):  
Anja Konietzny ◽  
Jasper Grendel ◽  
Alan Kadek ◽  
Michael Bucher ◽  
Yuhao Han ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Myosin V ◽  
Spine Apparatus
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