scholarly journals Correlative nanophotonic approaches to enlighten the nanoscale dynamics of living cell membranes

2021 ◽  
Author(s):  
Pamina M. Winkler ◽  
María F. García-Parajo
Keyword(s):  
Extracellular Matrix ◽  
Cell Membrane ◽  
Actin Cytoskeleton ◽  
Single Molecule ◽  
Living Cell ◽  
Cell Membranes ◽  
Cell Function ◽  
Membrane Dynamics ◽  
Correlation Spectroscopy ◽  
Spatiotemporal Resolution

Dynamic compartmentalization is a prevailing principle regulating the spatiotemporal organization of the living cell membrane from the nano- up to the mesoscale. This non-arbitrary organization is intricately linked to cell function. On living cell membranes, dynamic domains or ‘membrane rafts' enriched with cholesterol, sphingolipids and other certain proteins exist at the nanoscale serving as signaling and sorting platforms. Moreover, it has been postulated that other local organizers of the cell membrane such as intrinsic protein interactions, the extracellular matrix and/or the actin cytoskeleton synergize with rafts to provide spatiotemporal hierarchy to the membrane. Elucidating the intricate coupling of multiple spatial and temporal scales requires the application of correlative techniques, with a particular need for simultaneous nanometer spatial precision and microsecond temporal resolution. Here, we review novel fluorescence-based techniques that readily allow to decode nanoscale membrane dynamics with unprecedented spatiotemporal resolution and single-molecule sensitivity. We particularly focus on correlative approaches from the field of nanophotonics. Notably, we introduce a versatile planar nanoantenna platform combined with fluorescence correlation spectroscopy to study spatiotemporal heterogeneities on living cell membranes at the nano- up to the mesoscale. Finally, we outline remaining future technological challenges and comment on potential directions to advance our understanding of cell membrane dynamics under the influence of the actin cytoskeleton and extracellular matrix in uttermost detail.

Simultaneous manipulation and detection of living cell membrane dynamics

2007 ◽  
Vol 32 (13) ◽  
pp. 1893 ◽  
Author(s):  
Michael Gögler ◽  
Timo Betz ◽  
Josef Alfons Käs
Keyword(s):  
Cell Membrane ◽  
Living Cell ◽  
Membrane Dynamics

Assessing the single-molecule interactions between targeted peptides and the receptors on living cell membrane

Nanoscale ◽  
2021 ◽  
Author(s):  
Siying Li ◽  
Xuelei Pang ◽  
Jing Zhao ◽  
Qingrong Zhang ◽  
Yuping Shan
Keyword(s):  
Drug Delivery ◽  
Cell Membrane ◽  
Single Molecule ◽  
Living Cell ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Molecule Interactions

As one of potential ligands, targeted peptides have become an important part for construction intelligent drug delivery systems (DDSs). The targeting interaction of peptides with the receptors is a key...

scholarly journals Role of the Rho-ROCK (Rho-Associated Kinase) Signaling Pathway in the Regulation of Pancreatic β-Cell Function

Endocrinology ◽  
2008 ◽  
Vol 150 (5) ◽  
pp. 2072-2079 ◽  
Author(s):  
Eva Hammar ◽  
Alejandra Tomas ◽  
Domenico Bosco ◽  
Philippe A. Halban
Keyword(s):  
Extracellular Matrix ◽  
Insulin Secretion ◽  
Actin Cytoskeleton ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Β Cell Function ◽  
Glucose Stimulated Insulin Secretion ◽  
And Function

Extracellular matrix has a beneficial impact on β-cell spreading and function, but the underlying signaling pathways have yet to be fully elucidated. In other cell types, Rho, a well-characterized member of the family of Rho GTPases, and its effector Rho-associated kinase (ROCK), play an important role as downstream mediators of outside in signaling from extracellular matrix. Therefore, a possible role of the Rho-ROCK pathway in β-cell spreading, actin cytoskeleton dynamics, and function was investigated. Rho was inhibited using a new cell-permeable version of C3 transferase, whereas the activity of ROCK was repressed using the specific ROCK inhibitors H-1152 and Y-27632. Inhibition of Rho and of ROCK increased spreading and improved both short-term and prolonged glucose-stimulated insulin secretion but had no impact on basal secretion. Inhibition of this pathway led to a depolymerization of the actin cytoskeleton. Furthermore, the impact of the inhibition of ROCK on stimulated insulin secretion was acute and reversible, suggesting that rapid signaling such as phosphorylation is involved. Finally, quantification of the activity of RhoA indicated that the extracellular matrix represses RhoA activity. Overall these results show for the first time that the Rho-ROCK signaling pathway contributes to the stabilization of the actin cytoskeleton and inhibits glucose-stimulated insulin secretion in primary pancreatic β-cells. Furthermore, they indicate that inhibition of this pathway might be one of the mechanisms by which the extracellular matrix exerts its beneficial effects on pancreatic β-cell function.

scholarly journals Single-Molecule Imaging of Wnt3A Protein Diffusion on Living Cell Membranes

2017 ◽  
Vol 113 (12) ◽  
pp. 2762-2767 ◽  
Author(s):  
Anna Lippert ◽  
Agnieszka A. Janeczek ◽  
Alexandre Fürstenberg ◽  
Aleks Ponjavic ◽  
W.E. Moerner ◽  
...  
Keyword(s):  
Single Molecule ◽  
Living Cell ◽  
Cell Membranes ◽  
Single Molecule Imaging ◽  
Protein Diffusion

scholarly journals Diffusion of lipids and GPI-anchored proteins in actin-free plasma membrane vesicles measured by STED-FCS

2017 ◽  
Vol 28 (11) ◽  
pp. 1507-1518 ◽  
Author(s):  
Falk Schneider ◽  
Dominic Waithe ◽  
Mathias P. Clausen ◽  
Silvia Galiani ◽  
Thomas Koller ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Actin Cytoskeleton ◽  
High Mobility ◽  
Membrane Vesicles ◽  
Free Cell ◽  
Membrane Dynamics ◽  
Correlation Spectroscopy ◽  
Live Cell ◽  
Plasma Membrane Vesicles ◽  
Hindered Diffusion

Diffusion and interaction dynamics of molecules at the plasma membrane play an important role in cellular signaling and are suggested to be strongly associated with the actin cytoskeleton. Here we use superresolution STED microscopy combined with fluorescence correlation spectroscopy (STED-FCS) to access and compare the diffusion characteristics of fluorescent lipid analogues and GPI-anchored proteins (GPI-APs) in the live-cell plasma membrane and in actin cytoskeleton–free, cell-derived giant plasma membrane vesicles (GPMVs). Hindered diffusion of phospholipids and sphingolipids is abolished in the GPMVs, whereas transient nanodomain incorporation of ganglioside lipid GM1 is apparent in both the live-cell membrane and GPMVs. For GPI-APs, we detect two molecular pools in living cells; one pool shows high mobility with transient incorporation into nanodomains, and the other pool forms immobile clusters, both of which disappear in GPMVs. Our data underline the crucial role of the actin cortex in maintaining hindered diffusion modes of many but not all of the membrane molecules and highlight a powerful experimental approach to decipher specific influences on molecular plasma membrane dynamics.

scholarly journals The membrane-actin linker ezrin acts as a sliding anchor

2021 ◽  
Author(s):  
Elgin Korkmazhan ◽  
Alexander Robert Dunn
Keyword(s):  
Cell Membrane ◽  
Actin Cytoskeleton ◽  
Cell Motility ◽  
Single Molecule ◽  
Molecular Mechanisms ◽  
Optical Trap ◽  
Trap Assay ◽  
Rapid Changes

Protein linkages to filamentous (F)-actin provide the cell membrane with mechanical resiliency and give rise to intricate membrane architectures. However, the actin cytoskeleton is highly dynamic, and undergoes rapid changes in shape during cell motility and other processes. The molecular mechanisms that underlie the mechanically robust yet fluid connection between the membrane and actin cytoskeleton remain poorly understood. Here, we used a single-molecule optical trap assay to examine how the prototypical membrane-actin linker ezrin acts to anchor F-actin to the cell membrane. Remarkably, we find that ezrin forms a complex that slides along F-actin over micron distances while resisting mechanical detachment. The ubiquity of ezrin and analogous proteins suggests that sliding anchors such as ezrin may constitute an important but overlooked element in the construction of the actin cytoskeleton.

Sign in / Sign up

Export Citation Format

Share Document