The patterned assembly and stepwise Vps4-mediated disassembly of composite ESCRT-III polymers drives archaeal cell division

ESCRT-III family proteins form composite polymers that deform and cut membrane tubes in the context of a wide range of cell biological processes across the tree of life. In reconstituted systems sequential changes in the composition of ESCRT-III polymers induced by the AAA ATPase Vps4 have been shown to remodel membranes. However, it is not known how composite ESCRT-III polymers are organised and remodelled in space and time in cells. Here, taking advantage of the relative simplicity of the ESCRT-III-dependent division system in Sulfolobus acidocaldarius, one of the closest experimentally tractable prokaryotic relative of eukaryotes, we use super-resolution microscopy and computational modelling to show how CdvB/CdvB1/CdvB2 proteins form a precisely patterned composite ESCRT-III division ring which undergoes stepwise Vps4-dependent disassembly and contracts to cut cells into two. These observations lead us to suggest sequential changes in a patterned composite polymer as a general mechanism of ESCRT-III-dependent membrane remodelling.