@article{9414,
  abstract     = {Microtubule plus-end depolymerization rate is a potentially important target of physiological regulation, but it has been challenging to measure, so its role in spatial organization is poorly understood. Here we apply a method for tracking plus ends based on time difference imaging to measure depolymerization rates in large interphase asters growing in Xenopus egg extract. We observed strong spatial regulation of depolymerization rates, which were higher in the aster interior compared with the periphery, and much less regulation of polymerization or catastrophe rates. We interpret these data in terms of a limiting component model, where aster growth results in lower levels of soluble tubulin and microtubule-associated proteins (MAPs) in the interior cytosol compared with that at the periphery. The steady-state polymer fraction of tubulin was ∼30%, so tubulin is not strongly depleted in the aster interior. We propose that the limiting component for microtubule assembly is a MAP that inhibits depolymerization, and that egg asters are tuned to low microtubule density.},
  author       = {Ishihara, Keisuke and Decker, Franziska and Dos Santos Caldas, Paulo R and Pelletier, James F. and Loose, Martin and Brugués, Jan and Mitchison, Timothy J.},
  issn         = {1939-4586},
  journal      = {Molecular Biology of the Cell},
  number       = {9},
  pages        = {869--879},
  publisher    = {American Society for Cell Biology},
  title        = {{Spatial variation of microtubule depolymerization in large asters}},
  doi          = {10.1091/MBC.E20-11-0723},
  volume       = {32},
  year         = {2021},
}

@inbook{7572,
  abstract     = {The polymerization–depolymerization dynamics of cytoskeletal proteins play essential roles in the self-organization of cytoskeletal structures, in eukaryotic as well as prokaryotic cells. While advances in fluorescence microscopy and in vitro reconstitution experiments have helped to study the dynamic properties of these complex systems, methods that allow to collect and analyze large quantitative datasets of the underlying polymer dynamics are still missing. Here, we present a novel image analysis workflow to study polymerization dynamics of active filaments in a nonbiased, highly automated manner. Using treadmilling filaments of the bacterial tubulin FtsZ as an example, we demonstrate that our method is able to specifically detect, track and analyze growth and shrinkage of polymers, even in dense networks of filaments. We believe that this automated method can facilitate the analysis of a large variety of dynamic cytoskeletal systems, using standard time-lapse movies obtained from experiments in vitro as well as in the living cell. Moreover, we provide scripts implementing this method as supplementary material.},
  author       = {Dos Santos Caldas, Paulo R and Radler, Philipp and Sommer, Christoph M and Loose, Martin},
  booktitle    = {Methods in Cell Biology},
  editor       = {Tran, Phong },
  issn         = {0091679X},
  pages        = {145--161},
  publisher    = {Elsevier},
  title        = {{Computational analysis of filament polymerization dynamics in cytoskeletal networks}},
  doi          = {10.1016/bs.mcb.2020.01.006},
  volume       = {158},
  year         = {2020},
}

@article{7197,
  abstract     = {During bacterial cell division, the tubulin-homolog FtsZ forms a ring-like structure at the center of the cell. This Z-ring not only organizes the division machinery, but treadmilling of FtsZ filaments was also found to play a key role in distributing proteins at the division site. What regulates the architecture, dynamics and stability of the Z-ring is currently unknown, but FtsZ-associated proteins are known to play an important role. Here, using an in vitro reconstitution approach, we studied how the well-conserved protein ZapA affects FtsZ treadmilling and filament organization into large-scale patterns. Using high-resolution fluorescence microscopy and quantitative image analysis, we found that ZapA cooperatively increases the spatial order of the filament network, but binds only transiently to FtsZ filaments and has no effect on filament length and treadmilling velocity. Together, our data provides a model for how FtsZ-associated proteins can increase the precision and stability of the bacterial cell division machinery in a switch-like manner.},
  author       = {Dos Santos Caldas, Paulo R and Lopez Pelegrin, Maria D and Pearce, Daniel J. G. and Budanur, Nazmi B and Brugués, Jan and Loose, Martin},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  publisher    = {Springer Nature},
  title        = {{Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA}},
  doi          = {10.1038/s41467-019-13702-4},
  volume       = {10},
  year         = {2019},
}