Abstract:
:Actin is ubiquitous globular protein that polymerizes into filaments and forms networks that participate in the force generation of eukaryotic cells. Such forces are used for cell motility, cytokinesis, and tissue remodeling. Among those actin networks, we focus on the actin cortex, a dense branched network beneath the plasma membrane that is of particular importance for the mechanical properties of the cell. Here we reproduce the cellular cortex by activating actin filament growth on a solid surface. We unveil the existence of a sparse actin network that emanates from the surface and extends over a distance that is at least 10 times larger than the cortex itself. We call this sparse actin network the "actin cloud" and characterize its mechanical properties with optical tweezers. We show, both experimentally and theoretically, that the actin cloud is mechanically relevant and that it should be taken into account because it can sustain forces as high as several picoNewtons (pN). In particular, it is known that in plant cells, actin networks similar to the actin cloud have a role in positioning the nucleus; in large oocytes, they play a role in driving chromosome movement. Recent evidence shows that such networks even prevent granule condensation in large cells.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Bussonnier M,Carvalho K,Lemière J,Joanny JF,Sykes C,Betz Tdoi
10.1016/j.bpj.2014.07.008subject
Has Abstractpub_date
2014-08-19 00:00:00pages
854-62issue
4eissn
0006-3495issn
1542-0086pii
S0006-3495(14)00724-3journal_volume
107pub_type
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