Remarkable structural transformations of actin bundles are driven by their initial polarity, motor activity, crosslinking, and filament treadmilling

Chandrasekaran, Aravind

Remarkable structural transformations of actin bundles are driven by their initial polarity, motor activity, crosslinking, and filament treadmilling

dc.contributor.advisor	Papoian, Garegin
dc.contributor.advisor	Upadhyaya, Arpita
dc.contributor.author	Chandrasekaran, Aravind
dc.date.accessioned	2019-06-14T10:48:41Z
dc.date.available	2019-06-14T10:48:41Z
dc.date.issued	2019
dc.description	This repository contains dataset required to reproduce essential results of the manuscript. Data includes input files to generate MEDYAN trajectories for all conditions studied and representative trajectories for a subset of conditions studied.	en_US
dc.description.abstract	Bundled actin structures play a key role in maintaining cellular shape, in aiding force transmission to and from extracellular substrates, and in affecting cellular motility. Recent studies have also brought to light new details on stress generation, force transmission and contractility of actin bundles. In this work, we are primarily interested in the question of what determines the stability of actin bundles and what network geometries do unstable bundles eventually transition to. To address this problem, we used the MEDYAN mechano-chemical force field, modeling several micron-long actin bundles in 3D, while accounting for a comprehensive set of chemical, mechanical and transport processes. We developed a hierarchical clustering algorithm for classification of the different long time scale morphologies in our study. Our main finding is that initially unipolar bundles are significantly more stable compared with an apolar initial configuration. Filaments within the latter bundles slide easily with respect to each other due to myosin activity, producing a loose network that can be subsequently severely distorted. At high myosin concentrations, a morphological transition to aster-like geometries was observed. We also investigated how actin treadmilling rates influence bundle dynamics, and found that enhanced treadmilling leads to network fragmentation and disintegration, while this process is opposed by myosin and crosslinking activities. Interestingly, treadmilling bundles with an initial apolar geometry eventually evolve to a whole gamut of network morphologies based on relative positions of filament ends, such as sarcomere-like organization. We found that apolar bundles show a remarkable sensitivity to environmental conditions, which may be important in enabling rapid cytoskeletal structural reorganization and adaptation in response to intracellular and extracellular cues.	en_US
dc.description.sponsorship	This work was supported by the National Science Foundation (https://www.nsf.gov/) grants NSF PHY-1607645 (AU and GP) and NSF CHE-1800418 (GP).	en_US
dc.description.uri	https://doi.org/10.1371/journal.pcbi.1007156
dc.identifier	https://doi.org/10.13016/hpka-smll
dc.identifier.uri	http://hdl.handle.net/1903/21856
dc.language.iso	en_US	en_US
dc.relation.isAvailableAt	Digital Repository at the University of Maryland	en_us
dc.relation.isAvailableAt	Chemistry & Biochemistry	en_us
dc.relation.isAvailableAt	College of Computer, Mathematical & Natural Sciences	en_us
dc.relation.isAvailableAt	University of Maryland (College Park, MD)	en_us
dc.subject	Cytoskeleton	en_US
dc.subject	MEDYAN	en_US
dc.subject	Actomyosin	en_US
dc.subject	actin bundle	en_US
dc.title	Remarkable structural transformations of actin bundles are driven by their initial polarity, motor activity, crosslinking, and filament treadmilling	en_US
dc.type	Dataset	en_US