@article{BreuerNowakIvakovetal.2017,
  author    = {Breuer, David and Nowak, Jacqueline and Ivakov, Alexander and Somssich, Marc and Persson, Staffan and Nikoloski, Zoran},
  title     = {System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells},
  series = {Proceedings of the National Academy of Sciences of the United States of America},
  volume    = {114},
  journal   = {Proceedings of the National Academy of Sciences of the United States of America},
  publisher = {National Acad. of Sciences},
  address   = {Washington},
  issn      = {0027-8424},
  doi       = {10.1073/pnas.1706711114},
  pages     = {E5741 -- E5749},
  year      = {2017},
  abstract  = {The actin cytoskeleton is an essential intracellular filamentous structure that underpins cellular transport and cytoplasmic streaming in plant cells. However, the system-level properties of actin-based cellular trafficking remain tenuous, largely due to the inability to quantify key features of the actin cytoskeleton. Here, we developed an automated image-based, network-driven framework to accurately segment and quantify actin cytoskeletal structures and Golgi transport. We show that the actin cytoskeleton in both growing and elongated hypocotyl cells has structural properties facilitating efficient transport. Our findings suggest that the erratic movement of Golgi is a stable cellular phenomenon that might optimize distribution efficiency of cell material. Moreover, we demonstrate that Golgi transport in hypocotyl cells can be accurately predicted from the actin network topology alone. Thus, our framework provides quantitative evidence for system-wide coordination of cellular transport in plant cells and can be readily applied to investigate cytoskeletal organization and transport in other organisms.},
  language  = {en}
}
@phdthesis{Wang2022,
  author    = {Wang, Yang},
  title     = {Role of the actin cytoskeleton in cellular morphogenesis at the shoot apical meristem of Arabidopsis thaliana},
  doi       = {10.25932/publishup-55908},
  school      = {Universit{\"a}t Potsdam},
  pages     = {130},
  year      = {2022},
  abstract  = {The morphogenesis of sessile plants is mainly driven by directional cell growth and cell division. The organization of their cytoskeleton and the mechanical properties of the cell wall greatly influence morphogenetic events in plants. It is well known that cortical microtubules (CMTs) contribute to directional growth by regulating the deposition of the cellulose microfibrils, as major cell wall fortifying elements. More recent findings demonstrate that mechanical stresses existing in cells and tissues influence microtubule organization. Also, in dividing cells, mechanical stress directions contribute to the orientation of the new cell wall. In comparison to the microtubule cytoskeleton, the role of the actin cytoskeleton in regulating shoot meristem morphogenesis has not been extensively studied. This thesis focuses on the functional relevance of the actin cytoskeleton during cell and tissue scale morphogenesis in the shoot apical meristem (SAM) of Arabidopsis thaliana. Visualization of transcriptional reporters indicates that ACTIN2 and ACTIN7 are two highly expressed actin genes in the SAM. A link between the actin cytoskeleton and SAM development derives from the observation that the act2-1 act7-1 double mutant has abnormal cell shape and perturbed phyllotactic patterns. Live-cell imaging of the actin cytoskeleton further shows that its organization correlates with cell shape, which indicates a potential role of actin in influencing cellular morphogenesis. In this thesis, a detailed characterization of the act2-1 act7-1 mutant reveals that perturbation of actin leads to more rectangular cellular geometries with more 90° cell internal angles, and higher incidences of four-way junctions (four cell boundaries intersecting together). This observation deviates from the conventional tricellular junctions found in epidermal cells. Quantitative cellular-level growth data indicates that such differences in the act2-1 act7-1 mutant arise due to the reduced accuracy in the placement of the new cell wall, as well as its mechanical maturation. Changes in cellular morphology observed in the act2-1 act7-1 mutant result in cell packing defects that subsequently compromise the flow of information among cells in the SAM.},
  language  = {en}
}
@article{HsuKrekhovTarantolaetal.2019,
  author    = {Hsu, H. F. and Krekhov, Andrey and Tarantola, Marco and Beta, Carsten and Bodenschatz, Eberhardt},
  title     = {Interplay between myosin II and actin dynamics in chemotactic amoeba},
  series = {New journal of physics : the open-access journal for physics},
  volume    = {21},
  journal   = {New journal of physics : the open-access journal for physics},
  number    = {11},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {1367-2630},
  doi       = {10.1088/1367-2630/ab5822},
  pages     = {15},
  year      = {2019},
  abstract  = {The actin cytoskeleton and its response to external chemical stimuli is fundamental to the mechano-biology of eukaryotic cells and their functions. One of the key players that governs the dynamics of the actin network is the motor protein myosin II. Based on a phase space embedding we have identified from experiments three phases in the cytoskeletal dynamics of starved Dictyostelium discoideum in response to a precisely controlled chemotactic stimulation. In the first two phases the dynamics of actin and myosin II in the cortex is uncoupled, while in the third phase the time scale for the recovery of cortical actin is determined by the myosin II dynamics. We report a theoretical model that captures the experimental observations quantitatively. The model predicts an increase in the optimal response time of actin with decreasing myosin II-actin coupling strength highlighting the role of myosin II in the robust control of cell contraction.},
  language  = {en}
}
@article{WelkeSperberBergmannetal.2022,
  author    = {Welke, Robert-William and Sperber, Hannah Sabeth and Bergmann, Ronny and Koikkarah, Amit and Menke, Laura and Sieben, Christian and Kr{\"u}ger, Detlev H. and Chiantia, Salvatore and Herrmann, Andreas and Schwarzer, Roland},
  title     = {Characterization of hantavirus N protein intracellular dynamics and localization},
  series = {Viruses},
  volume    = {14},
  journal   = {Viruses},
  number    = {3},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1999-4915},
  doi       = {10.3390/v14030457},
  pages     = {14},
  year      = {2022},
  abstract  = {Hantaviruses are enveloped viruses that possess a tri-segmented, negative-sense RNA genome. The viral S-segment encodes the multifunctional nucleocapsid protein (N), which is involved in genome packaging, intracellular protein transport, immunoregulation, and several other crucial processes during hantavirus infection. In this study, we generated fluorescently tagged N protein constructs derived from Puumalavirus (PUUV), the dominant hantavirus species in Central, Northern, and Eastern Europe. We comprehensively characterized this protein in the rodent cell line CHO-K1, monitoring the dynamics of N protein complex formation and investigating co-localization with host proteins as well as the viral glycoproteins Gc and Gn. We observed formation of large, fibrillar PUUV N protein aggregates, rapidly coalescing from early punctate and spike-like assemblies. Moreover, we found significant spatial correlation of N with vimentin, actin, and P-bodies but not with microtubules. N constructs also co-localized with Gn and Gc albeit not as strongly as the glycoproteins associated with each other. Finally, we assessed oligomerization of N constructs, observing efficient and concentration-dependent multimerization, with complexes comprising more than 10 individual proteins.},
  language  = {en}
}