Properties of Dp-actin [Dronpa (Dp)-labeled actin] in MCF-7 cells

Range diffusion coefficient of Dp-actin 13.7μm^2/s: halflife of mobile fraction 41ms: mobile fraction 79%
Organism Human Homo sapiens
Reference Kiuchi T, Nagai T, Ohashi K, Mizuno K. Measurements of spatiotemporal changes in G-actin concentration reveal its effect on stimulus-induced actin assembly and lamellipodium extension. J Cell Biol. 2011 Apr 18 193(2):365-80. doi: 10.1083/jcb.201101035. p.367 right columnPubMed ID21502360
Method P.366 right column 2nd paragraph:"In this study, [investigators] describe a novel approach for measuring time-dependent changes in G-actin concentration in live cells and provide evidence that G-actin concentration is an important parameter in determining the extents of stimulus-induced actin assembly and cell expansion."
Comments P.367 right column:"The rate of fluorescence decay was much faster than the turnover rate of actin filaments (Theriot and Mitchison, 1991 McGrath et al., 1998 Watanabe and Mitchison, 2002), indicating that the FDAP [fluorescence decay after photoactivation] values measured under these conditions reflect G-actin concentration (but not F-actin disassembly). By fitting the time curve of fluorescence decay (Fig. 1 E), the diffusion coefficient of Dp-actin, the half-life of the mobile fraction, and the mobile fraction were determined to be 13.7 μm^2/s, 41 ms, and 79%, respectively." Wiki:"MCF-7 is a breast cancer cell line isolated in 1970 from a 69-year-old Caucasian woman. MCF-7 is the acronym of Michigan Cancer Foundation-7..." Springer link link :"Mobile fraction denotes the percentage of fluorescent molecules in a sample available to contribute to fluorescence recovery during the time course of a FRAP (fluorescence recovery after photobleaching) experiment. Note that this measure is used to assess the mobility of fluorophores within a continuous compartment."
Entered by Uri M
ID 112132