Average diffusion coefficient (estimated using refined algorithm) of oligo(dT) in nucleus of HeLa cell

Value 0.32 µm^2/s Range: ±0.04 µm^2/s
Organism Human Homo sapiens
Reference Politz JC et al., Rapid, diffusional shuttling of poly(A) RNA between nuclear speckles and the nucleoplasm. Mol Biol Cell. 2006 Mar17(3):1239-49. p.1244 left column 3rd paragraphPubMed ID16371503
Method p.1243 right column bottom paragraph:"To visually track the movement of poly(A) RNA in and out of speckles and within the nucleoplasm, [investigators] next introduced oligo(dT) labeled with photoactivatable fluorescein (Mitchison et al., 1994 Politz, 1999 Politz et al., 1999) to the SC35-expressing HeLa cell line."
Comments p.1244 left column 3rd paragraph:"When the rate of movement away from the uncaging site was plotted as a function of the width (at e^–2) of the Gaussian distribution at increasing times (Cardullo et al., 1991), the mean square displacement of the signal was found to be linearly proportional to time (Figure 5C), as expected of a diffusive process. The average estimated diffusion coefficient using this method was 0.67 ± 0.05 µm2/s, which was very similar to that estimated earlier in the nucleoplasm of L6 cells using the same method (BNID 111845). Because this method of estimating a diffusion coefficient is dependent on the position at which the width of the Gaussian is measured, and also does not account for any potential optical blurring, [investigators] also used a more refined algorithm to estimate the diffusion coefficient. This algorithm fit the relative shapes of the entire Gaussian distributions over multiple time points with a two-component model (Figure 5B, smooth lines) to more accurately estimate a diffusion coefficient (Fogarty et al., 2000 Figure 6). Using this method, an average diffusion coefficient of 0.32 ± 0.04 µm^2/s was estimated."
Entered by Uri M
ID 111848