Gaining insight into cellular cardiac physiology using single particle tracking

2020 ◽  
Vol 148 ◽  
pp. 63-77
Author(s):  
Ying Li ◽  
Jing Yi ◽  
Wenjuan Liu ◽  
Yun Liu ◽  
Jie Liu
2019 ◽  
Author(s):  
Yerim Lee ◽  
Carey Phelps ◽  
Tao Huang ◽  
Barmak Mostofian ◽  
Lei Wu ◽  
...  

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.


Soft Matter ◽  
2020 ◽  
Vol 16 (9) ◽  
pp. 2256-2265 ◽  
Author(s):  
Emmabeth Parrish ◽  
Katie A. Rose ◽  
Matteo Cargnello ◽  
Christopher B. Murray ◽  
Daeyeon Lee ◽  
...  

Single particle tracking (SPT) of PEG grafted nanoparticles (NPs) was used to examine the gelation of tetra poly(ethylene glycol) (TPEG) succinimidyl glutarate (TPEG-SG) and amine (TPEG-A) terminated 4-armed stars.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yerim Lee ◽  
Carey Phelps ◽  
Tao Huang ◽  
Barmak Mostofian ◽  
Lei Wu ◽  
...  

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.


Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 498
Author(s):  
Chen Zhang ◽  
Kevin Welsher

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.


Soft Matter ◽  
2021 ◽  
Author(s):  
Katie A. Rose ◽  
Daeyeon Lee ◽  
Russell J. Composto

The effect of static silica particles on the dynamics of quantum dot (QD) nanoparticles grafted with a poly(ethylene glycol) (PEG) brush in hydrogel nanocomposites is investigated using single particle tracking (SPT).


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