Abstract:
:The cellular cytoplasm is a complex, heterogeneous environment (both spatially and temporally) that exhibits viscoelastic behavior. To further develop our quantitative insight into cellular transport, we analyze data sets of mRNA molecules fluorescently labeled with MS2-GFP tracked in real time in live Escherichia coli and Saccharomyces cerevisiae cells. As shown previously, these RNA-protein particles exhibit subdiffusive behavior that is viscoelastic in its origin. Examining the ensemble of particle displacements reveals a Laplace distribution at all observed timescales rather than the Gaussian distribution predicted by the central limit theorem. This ensemble non-Gaussian behavior is caused by a combination of an exponential distribution in the time-averaged diffusivities and non-Gaussian behavior of individual trajectories. We show that the non-Gaussian behavior is a consequence of significant heterogeneity between trajectories and dynamic heterogeneity along single trajectories. Informed by theory and simulation, our work provides an in-depth analysis of the complex diffusive behavior of RNA-protein particles in live cells.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Lampo TJ,Stylianidou S,Backlund MP,Wiggins PA,Spakowitz AJdoi
10.1016/j.bpj.2016.11.3208subject
Has Abstractpub_date
2017-02-07 00:00:00pages
532-542issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(16)34322-3journal_volume
112pub_type
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