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Confined diffusion of transmembrane proteins and lipids induced by the same actin meshwork lining the plasma membrane.

Fujiwara TK, Iwasawa K, Kalay Z, Tsunoyama TA, Watanabe Y, Umemura YM, Murakoshi H, Suzuki KG, Nemoto YL, Morone N, Kusumi A - Mol. Biol. Cell (2016)

Bottom Line: Electron tomography identified the actin-based membrane skeleton (MSK) located within 8.8 nm from the PM cytoplasmic surface of PtK2 cells and demonstrated that the MSK mesh size was the same as the compartment size for PM molecular diffusion.The extracellular matrix and extracellular domains of membrane proteins were not involved in hop diffusion.These results support a model of anchored TM-protein pickets lining actin-based MSK as a major mechanism for regulating diffusion.

View Article: PubMed Central - PubMed

Affiliation: Center for Meso-Bio Single-Molecule Imaging, Institute for Integrated Cell-Material Sciences, Kyoto 606-8501, Japan.

No MeSH data available.


Related in: MedlinePlus

Method for classifying the trajectories into simple-Brownian-, suppressed-, and directed-diffusion modes and its application to TfR and DOPE trajectories (with fluorescent and gold probes) obtained in the PtK2-PM at video rate. (A) Representative trajectories of TfR (left) and DOPE (right) tagged with Cy3 (top) or gold (bottom) probes in the PtK2-PM. (B) Left, theoretical MSD–Δt curves for 1) simple-Brownian, 2) directed, and 3) suppressed diffusion (for the same short-term diffusion coefficients = initial slope at time 0). Right, motional mode classification based on RD(N, n). (C) Distribution of RD(N, n) for N = 100 and n = 30 (1 s), used for the classification of the trajectories into different diffusion modes (left, TfR; right, DOPE). Top, simple-Brownian trajectories generated by Monte Carlo simulation (the same graphs are used for both TfR and DOPE). The 2.5th percentiles of the distribution from both ends, RDmin(100, 30) and RDMAX(100, 30), are shown by red and cyan vertical lines, respectively. Middle, SFMT at normal video rate, using Cy3 as a probe. Bottom, SPT at normal video rate, using gold particles as probes.
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Figure 2: Method for classifying the trajectories into simple-Brownian-, suppressed-, and directed-diffusion modes and its application to TfR and DOPE trajectories (with fluorescent and gold probes) obtained in the PtK2-PM at video rate. (A) Representative trajectories of TfR (left) and DOPE (right) tagged with Cy3 (top) or gold (bottom) probes in the PtK2-PM. (B) Left, theoretical MSD–Δt curves for 1) simple-Brownian, 2) directed, and 3) suppressed diffusion (for the same short-term diffusion coefficients = initial slope at time 0). Right, motional mode classification based on RD(N, n). (C) Distribution of RD(N, n) for N = 100 and n = 30 (1 s), used for the classification of the trajectories into different diffusion modes (left, TfR; right, DOPE). Top, simple-Brownian trajectories generated by Monte Carlo simulation (the same graphs are used for both TfR and DOPE). The 2.5th percentiles of the distribution from both ends, RDmin(100, 30) and RDMAX(100, 30), are shown by red and cyan vertical lines, respectively. Middle, SFMT at normal video rate, using Cy3 as a probe. Bottom, SPT at normal video rate, using gold particles as probes.

Mentions: Single-molecule images and trajectories of TfR tagged with Cy3-Tf (Cy3-TfR) in the apical PM of epithelial PtK2 cells were obtained with the same TIRF microscope at a slow rate (video rate) but with oblique-angle illumination (Figures 1Ca and 2A, top left), and each single-molecule trajectory was classified into the 1) simple-Brownian, 2) directed, or 3) suppressed diffusion mode in the following manner (Kusumi et al., 1993; Hiramoto-Yamaki et al., 2014).


Confined diffusion of transmembrane proteins and lipids induced by the same actin meshwork lining the plasma membrane.

Fujiwara TK, Iwasawa K, Kalay Z, Tsunoyama TA, Watanabe Y, Umemura YM, Murakoshi H, Suzuki KG, Nemoto YL, Morone N, Kusumi A - Mol. Biol. Cell (2016)

Method for classifying the trajectories into simple-Brownian-, suppressed-, and directed-diffusion modes and its application to TfR and DOPE trajectories (with fluorescent and gold probes) obtained in the PtK2-PM at video rate. (A) Representative trajectories of TfR (left) and DOPE (right) tagged with Cy3 (top) or gold (bottom) probes in the PtK2-PM. (B) Left, theoretical MSD–Δt curves for 1) simple-Brownian, 2) directed, and 3) suppressed diffusion (for the same short-term diffusion coefficients = initial slope at time 0). Right, motional mode classification based on RD(N, n). (C) Distribution of RD(N, n) for N = 100 and n = 30 (1 s), used for the classification of the trajectories into different diffusion modes (left, TfR; right, DOPE). Top, simple-Brownian trajectories generated by Monte Carlo simulation (the same graphs are used for both TfR and DOPE). The 2.5th percentiles of the distribution from both ends, RDmin(100, 30) and RDMAX(100, 30), are shown by red and cyan vertical lines, respectively. Middle, SFMT at normal video rate, using Cy3 as a probe. Bottom, SPT at normal video rate, using gold particles as probes.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4814218&req=5

Figure 2: Method for classifying the trajectories into simple-Brownian-, suppressed-, and directed-diffusion modes and its application to TfR and DOPE trajectories (with fluorescent and gold probes) obtained in the PtK2-PM at video rate. (A) Representative trajectories of TfR (left) and DOPE (right) tagged with Cy3 (top) or gold (bottom) probes in the PtK2-PM. (B) Left, theoretical MSD–Δt curves for 1) simple-Brownian, 2) directed, and 3) suppressed diffusion (for the same short-term diffusion coefficients = initial slope at time 0). Right, motional mode classification based on RD(N, n). (C) Distribution of RD(N, n) for N = 100 and n = 30 (1 s), used for the classification of the trajectories into different diffusion modes (left, TfR; right, DOPE). Top, simple-Brownian trajectories generated by Monte Carlo simulation (the same graphs are used for both TfR and DOPE). The 2.5th percentiles of the distribution from both ends, RDmin(100, 30) and RDMAX(100, 30), are shown by red and cyan vertical lines, respectively. Middle, SFMT at normal video rate, using Cy3 as a probe. Bottom, SPT at normal video rate, using gold particles as probes.
Mentions: Single-molecule images and trajectories of TfR tagged with Cy3-Tf (Cy3-TfR) in the apical PM of epithelial PtK2 cells were obtained with the same TIRF microscope at a slow rate (video rate) but with oblique-angle illumination (Figures 1Ca and 2A, top left), and each single-molecule trajectory was classified into the 1) simple-Brownian, 2) directed, or 3) suppressed diffusion mode in the following manner (Kusumi et al., 1993; Hiramoto-Yamaki et al., 2014).

Bottom Line: Electron tomography identified the actin-based membrane skeleton (MSK) located within 8.8 nm from the PM cytoplasmic surface of PtK2 cells and demonstrated that the MSK mesh size was the same as the compartment size for PM molecular diffusion.The extracellular matrix and extracellular domains of membrane proteins were not involved in hop diffusion.These results support a model of anchored TM-protein pickets lining actin-based MSK as a major mechanism for regulating diffusion.

View Article: PubMed Central - PubMed

Affiliation: Center for Meso-Bio Single-Molecule Imaging, Institute for Integrated Cell-Material Sciences, Kyoto 606-8501, Japan.

No MeSH data available.


Related in: MedlinePlus