scholarly journals Decision letter: High-throughput, single-particle tracking reveals nested membrane domains that dictate KRasG12D diffusion and trafficking

2019 ◽  
Keyword(s):  
High Throughput ◽  
Particle Tracking ◽  
Single Particle ◽  
Single Particle Tracking ◽  
Membrane Domains

scholarly journals High-throughput single-particle tracking reveals nested membrane nanodomain organization that dictates Ras diffusion and trafficking

2019 ◽  
Author(s):  
Yerim Lee ◽  
Carey Phelps ◽  
Tao Huang ◽  
Barmak Mostofian ◽  
Lei Wu ◽  
...  
Keyword(s):  
High Throughput ◽  
Particle Tracking ◽  
Single Particle ◽  
Single Particle Tracking ◽  
Ras Signaling ◽  
Fast Diffusion ◽  
Membrane Domains ◽  
Spatial Mechanisms ◽  
Insight Into ◽  
Distinct Membrane

AbstractMembrane nanodomains have been implicated in Ras signaling, but what these domains are and how they interact with Ras remain obscure. Using high throughput single particle tracking with photoactivated localization microscopy and detailed trajectory analysis, here we show that distinct membrane domains dictate KRas diffusion and trafficking in U2OS cells. KRas exhibits an immobile state in domains ∼70 nm in size, each embedded in a larger domain (∼200 nm) that confers intermediate mobility, while the rest of the membrane supports fast diffusion. Moreover, KRas is continuously removed from the membrane via the immobile state and replenished to the fast state, likely coupled to internalization and recycling. Importantly, both the diffusion and trafficking properties of KRas remain invariant over a broad range of protein expression levels. Our results reveal how membrane organization dictates KRas diffusion and trafficking and offer insight into how Ras signaling may be regulated through spatial mechanisms.

scholarly journals Organization of the axon initial segment: Actin like a fence

2016 ◽  
Vol 215 (1) ◽  
pp. 9-11 ◽  
Author(s):  
Yu-Mei Huang ◽  
Matthew N. Rasband
Keyword(s):  
Particle Tracking ◽  
Single Particle ◽  
High Speed ◽  
Initial Segment ◽  
Single Particle Tracking ◽  
Axon Initial Segment ◽  
Membrane Domains ◽  
Superresolution Microscopy ◽  
Cell Biol ◽  
Actin Rings

What prevents the movement of membrane molecules between axonal and somatodendritic domains is unclear. In this issue, Albrecht et. al. (2016. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201603108) demonstrate via high-speed single-particle tracking and superresolution microscopy that lipid-anchored molecules in the axon initial segment are confined to membrane domains separated by periodically spaced actin rings.

scholarly journals Nanoplastic Sizes and Numbers: Quantification by Single Particle Tracking

2020 ◽  
Author(s):  
Robert Molenaar ◽  
Swarupa Chatterjee ◽  
Mireille M. A. E Claessens ◽  
Christian Blum
Keyword(s):  
High Throughput ◽  
Particle Tracking ◽  
Single Particle ◽  
Environmental Samples ◽  
Single Particle Tracking ◽  
Water Bodies ◽  
High Throughput Analysis ◽  
Mixing Ratios ◽  
Almost Everywhere ◽  
Terrestrial Water

<p>Plastic particles have been found almost everywhere in the environment, in oceans, terrestrial water bodies, sediments and air. The extend of this unwanted contamination is difficult to fully capture. Existing quantification methods focus on the detection of millimeter to micrometer sized plastic particles, while plastic breakdown processes continue to smaller, nanometer sized, particles. For these nanoplastics methods that are inexpensive and can be (semi-) automated for high throughput analysis of dilute nanoplastic particle suspensions, are lacking. ​​​​​​​​​​​​​​Here we combine sensitive fluorescence video microsopy, NileRed staining of plastic particles, and Single Particle Tracking (SPT) to count and size nanoplastics. With this approach we show that particle diameters as low as 40 nm can be extracted, mixing ratios can be recovered, and number concentrations as low as 2·10<sup>6</sup> particles/ml can be determined. These results indicate that this approach is promising for the quantification of sizes and concentrations of nanoplastics in environmental samples.</p>

scholarly journals Nanoplastic Sizes and Numbers: Quantification by Single Particle Tracking

2020 ◽  
Author(s):  
Robert Molenaar ◽  
Swarupa Chatterjee ◽  
Mireille M. A. E Claessens ◽  
Christian Blum
Keyword(s):  
High Throughput ◽  
Particle Tracking ◽  
Single Particle ◽  
Environmental Samples ◽  
Single Particle Tracking ◽  
Water Bodies ◽  
High Throughput Analysis ◽  
Mixing Ratios ◽  
Almost Everywhere ◽  
Terrestrial Water

<p>Plastic particles have been found almost everywhere in the environment, in oceans, terrestrial water bodies, sediments and air. The extend of this unwanted contamination is difficult to fully capture. Existing quantification methods focus on the detection of millimeter to micrometer sized plastic particles, while plastic breakdown processes continue to smaller, nanometer sized, particles. For these nanoplastics methods that are inexpensive and can be (semi-) automated for high throughput analysis of dilute nanoplastic particle suspensions, are lacking. ​​​​​​​​​​​​​​Here we combine sensitive fluorescence video microsopy, NileRed staining of plastic particles, and Single Particle Tracking (SPT) to count and size nanoplastics. With this approach we show that particle diameters as low as 40 nm can be extracted, mixing ratios can be recovered, and number concentrations as low as 2·10<sup>6</sup> particles/ml can be determined. These results indicate that this approach is promising for the quantification of sizes and concentrations of nanoplastics in environmental samples.</p>

scholarly journals High-throughput, single-particle tracking reveals nested membrane domains that dictate KRasG12D diffusion and trafficking

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yerim Lee ◽  
Carey Phelps ◽  
Tao Huang ◽  
Barmak Mostofian ◽  
Lei Wu ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Single Particle ◽  
Single Particle Tracking ◽  
Ras Signaling ◽  
Fast Diffusion ◽  
Membrane Domains ◽  
Membrane Diffusion ◽  
Spatial Regulation ◽  
Insight Into ◽  
Distinct Membrane

Membrane nanodomains have been implicated in Ras signaling, but what these domains are and how they interact with Ras remain obscure. Here, using single particle tracking with photoactivated localization microscopy (spt-PALM) and detailed trajectory analysis, we show that distinct membrane domains dictate KRasG12D (an active KRas mutant) diffusion and trafficking in U2OS cells. KRasG12D exhibits an immobile state in ~70 nm domains, each embedded in a larger domain (~200 nm) that confers intermediate mobility, while the rest of the membrane supports fast diffusion. Moreover, KRasG12D is continuously removed from the membrane via the immobile state and replenished to the fast state, reminiscent of Ras internalization and recycling. Importantly, both the diffusion and trafficking properties of KRasG12D remain invariant over a broad range of protein expression levels. Our results reveal how membrane organization dictates membrane diffusion and trafficking of Ras and offer new insight into the spatial regulation of Ras signaling.

scholarly journals Information-Efficient, Off-Center Sampling Results in Improved Precision in 3D Single-Particle Tracking Microscopy

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 498
Author(s):  
Chen Zhang ◽  
Kevin Welsher
Keyword(s):  
Fisher Information ◽  
Particle Tracking ◽  
Single Particle ◽  
Biological Samples ◽  
Tracking System ◽  
Single Particle Tracking ◽  
Uniform Sampling ◽  
Single Dimension ◽  
3D Localization ◽  
Particle Localization

In this work, we present a 3D single-particle tracking system that can apply tailored sampling patterns to selectively extract photons that yield the most information for particle localization. We demonstrate that off-center sampling at locations predicted by Fisher information utilizes photons most efficiently. When performing localization in a single dimension, optimized off-center sampling patterns gave doubled precision compared to uniform sampling. A ~20% increase in precision compared to uniform sampling can be achieved when a similar off-center pattern is used in 3D localization. Here, we systematically investigated the photon efficiency of different emission patterns in a diffraction-limited system and achieved higher precision than uniform sampling. The ability to maximize information from the limited number of photons demonstrated here is critical for particle tracking applications in biological samples, where photons may be limited.

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