Many proteins that were once thought to be unique to eukaryotes are now known to have their origins in archaea. These include ESCRT-III and AAA-ATPase Vps4 proteins. In eukaryotes, homologues of these proteins are known to cut biological membrane tubes from the inside - an activity that is critical for a wide range of membrane remodelling events, including membrane repair, multi-vesicular body formation, viral release and the final stages of cell division, when one cell is cut into two. Strikingly, homologues of these proteins appear to have a similar activity in TACK-family archaea, such as Sulfolobus, where they play a role in division. This enables Sulfolobus to be used as a simple system in which to better understand the physical mechanism of ESCRT-III mediated scission.
Recent work by the lab suggests a novel, but relatively simple physical model for this process, in which cell division in Sulfolobus is driven by the stepwise assembly and remodelling of a hetero-polymeric ESCRT-III ring.
In this PhD project, the student will combine archaeal cell biology (imaging cells at 75°C), biochemistry and a structural analysis of division rings to test this model and to explore the role of two AAA-ATPases in the closure of the ESCRT-III ring. In doing so, they will help refine our picture of ESCRT-III-mediated cell division in archaea. At the same time, we expect this work to shed light on the origins and evolution of cell division in eukaryotes.
For inquiries contact Cell Biology Head of Division Sean Munro.
G Tarrason Risa, F Hurtig… A Šarić, AC Lindås, N Robinson, B Baum.
Proteasome-mediated protein degradation resets the cell division cycle and triggers ESCRT-III-mediated cytokinesis in an archaeon.
bioRxiv 774273; doi: https://doi.org/10.1101/774273
L Harker-Kirschneck, B Baum, A Šarić. (2019)
Changes in ESCRT-III filament geometry drive membrane remodelling and fission in silico.
BMC biology, 17 (1), 1-8.
CL Dix, HK Matthews, M Uroz, S McLaren, L Wolf, N Heatley, Z Win, ...B Baum. (2018).
The role of mitotic cell-substrate adhesion re-modeling in animal cell division.
Developmental Cell, 45, 132-145.
G Dey, M Thattai, B Baum. (2016).
On the archaeal origins of eukaryotes and the challenges of inferring phenotype from genotype.
Trends in Cell Biology, 26, 476-485.
NTL Rodrigues, S Lekomtsev, S Jananji, J Kriston-Vizi, GRX Hickson, ...B Baum. (2015).
Kinetochore-localized PP1–Sds22 couples chromosome segregation to polar relaxation.
Nature, 524, 489-492.
Mierzwa B, Gerlich DW. (2014).
Cytokinetic abscission: molecular mechanisms and temporal control.
Dev Cell. 31, 525-538.
D Baum, B Baum. (2014).
A inside-out origin for eukaryote cells.
BMC Biology, 12, 76.
Lindås AC, Bernander R. (2013).
The cell cycle of archaea.
Nat Rev Microbiol. 11, 627-638.