posted on 2021-05-14, 17:41authored byJessica
G. Bermudez, Alexander Deiters, Matthew C. Good
Eukaryotic cells
contain a cytoskeletal network comprised of dynamic
microtubule filaments whose spatial organization is highly plastic.
Specialized microtubule architectures are optimized for different
cell types and remodel with the oscillatory cell cycle. These spatially
distinct microtubule networks are thought to arise from the activity
and localization of microtubule regulators and motors and are further
shaped by physical forces from the cell boundary. Given complexities
and redundancies of a living cell, it is challenging to disentangle
the separate biochemical and physical contributions to microtubule
network organization. Therefore, we sought to develop a minimal cell-like
system to manipulate and spatially pattern the organization of cytoskeletal
components in real-time, providing an opportunity to build distinct
spatial structures and to determine how they are shaped by or reshape
cell boundaries. We constructed a system for induced spatial patterning
of protein components within cell-sized emulsion compartments and
used it to drive microtubule network organization in real-time. We
controlled dynamic protein relocalization using small molecules and
light and slowed lateral diffusion within the lipid monolayer to create
stable micropatterns with focused illumination. By fusing microtubule
interacting proteins to optochemical dimerization domains, we directed
the spatial organization of microtubule networks. Cortical patterning
of polymerizing microtubules leads to symmetry breaking and forces
that dramatically reshape the compartment. Our system has applications
in cell biology to characterize the contributions of biochemical components
and physical boundary conditions to microtubule network organization.
Additionally, active shape control has uses in protocell engineering
and for augmenting the functionalities of synthetic cells.