The final cut: cell division in archaeaGroup Leader Page
Cell division is one of the most remarkable processes in all of biology. To generate two viable daughter cells, the contractile division ring must be assembled at the cell centre and properly oriented so that it bisects the cell between the two segregating copies of the genome.
Following the recent discovery that eukaryotic cells inherited much of their division machinery from archaeal ancestors (1), our lab has been using Sulfolobus - the closest experimentally tractable archaeal relative of eukaryotes - as a simple model by which to understand the fundamentals and evolution of this process.
Through this work the team recently identified a role for the proteasome in determining the timing of cell division in Sulfolobus (2). More specifically, we showed that the sudden degradation of a single component of the composite ESCRT-III-based division ring triggers a change in polymer structure that drives cytokinesis (2, 3). Importantly, a computational model of ESCRT-III-dependent membrane remodelling developed together with the Saric lab (4) supports this being a physically plausible mechanism of division. In addition, the model makes predictions about the dynamics and structural features of the process.
In putting these ideas to the test, the PhD student joining the team will use a combination of live cell imaging, molecular genetics and structural approaches to try and determine the physical mechanism(s) of ESCRT-III dependent cytokinesis. Ultimately, we expect this research to reveal mechanistic details of the division process that are specific to Sulfolobus; as well as general principles that can be applied to our understanding of cell division across the tree of life.
Baum, Baum, (2020)
The merger that made us.
BMC biology 18 (1), 1-4.
Tarrason Risa et al., (2020)
Proteasome controls ESCRT-III-mediated cell division in an archaeon.
Science 369 (6504).
Pulschen et al., (2020)
Live Imaging of a Hyperthermophilic Archaeon Reveals Distinct Roles for Two ESCRT-III Homologs in Ensuring a Robust and Symmetric Division.
Current Biology 30, 1–8.
L. Harker-Kirschneck et al.
Physical mechanisms of ESCRT-III-driven cell division in archaea.