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Sundmacher, K.

Publications and source records attributed to Sundmacher, K..

2 recordsLinked to original sources

Light-powered reactivation of flagella: towards self-sustained movement of artificial cells

Artificial systems capable of self-sustained movement with self-sufficient energy are of high interest with respect to the development of many challenging applications including medical treatments but also technical applications. The bottom-up assembly of such systems in the context of synthetic biology is still a challenging task. In this work, we demonstrate the biocompatibility and efficiency of an artificial light-driven energy module and a motility functional unit by integrating light-switchable photosynthetic vesicles with demembranated flagella that provide ATP for dynein molecular motors upon illumination. The flagellar propulsion is coupled to the beating frequency and dynamic ATP synthesis in response to illumination allows us to control beating frequency of flagella in a light-dependent manner. In addition, we verified the functionality of light-powered synthetic vesicles in in vitro motility assays by encapsulating microtubules assembled with force-generating kinesin-1 motors and the energy module to investigate the dynamics of a contractile filamentous network in cell-like compartments by optical stimulation. Integration of this photosynthetic system with various biological building blocks such as cytoskeletal filaments and molecular motors may contribute to the bottom-up synthesis of artificial cells that are able to undergo motor-driven morphological deformations and exhibit directional motion in a light-controllable fashion. Graphical TOC Entry O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=82 SRC="FIGDIR/small/212191v3_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@79347aorg.highwire.dtl.DTLVardef@164463dorg.highwire.dtl.DTLVardef@3f8b01org.highwire.dtl.DTLVardef@1bef3e8_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

Cortical Actomyosin Flows are Generated by Actomyosin Cluster Vibrations in Vitro

Cortical actomyosin flows play pivotal roles in cell motility, cell division and animal morphogenesis. According to many model systems, myosin motor induced local contractions are key for generating cortical flows. However, the original mechanism how large-scale directed flows emerge from local motor activity in an apparently isotropic cortex is unknown. We reconstituted and confined minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced cortical contractions that self-organize into directed flow-like actomyosin motions. By combining our experiments with theory, we found that the large-scale directional motion of actomyosin clusters emerges from individual asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption, in conjunction with spherical confinement. By tracking individual actomyosin clusters, we identified fingerprints of vibrational states as the basis of directed motions. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems.

synthetic biology↗