Cell Division

When the genomes of Sulfolobus and its relatives were first sequenced, it became apparent that they lacked homologs of the otherwise near-ubiquitous cytoskeletal proteins in the tubulin and actin superfamilies.  In a 2008 publication in Science we revealed that Sulfolobus cell division was mediated by orthologs of the eukaryotic ESCRT machinery. Eukaryotic ESCRTs are involved in a wide range of membrane manipulations including endosomal sorting, plasma membrane wound healing, mammalian abscission (the final stage of cytokinesis). In addition, a number of viruses hijack ESCRT to effect egress from infected cells. In collaboration with Roger William's lab at the MRC LMB in Cambridge we have investigated the mode of action of the archaeal ESCRT machinery using a combination of genetic, cell biological, biochemical and structural approaches. More recently, we have collaborated with Grant Jensen at CalTech to visualize cell division structures using cryoelectron tomography (right hand images above, see also animation below).

Additionally, with Mark Young at Montana State, we have uncovered a role for Sulfolobus ESCRT in the life-cycle of the Sulfolobus virus STIV.

Key Publications

R.Y Samson. M.J. Dobro, G.J. Jensen and S.D. Bell (2017) “The structure, function and roles of the archaeal ESCRT proteins”, Prokaryotic Cytoskeletons, Subcell Bioch. 84, 357-37

M. Dobro, R.Y. Samson, S.D. Bell, G. J. Jensen. (2013) “ Electron cryotomography of ESCRT assemblies and dividing Sulfolobus cells suggests that spiraling filaments are involved in membrane scission” Mol. Biol. Cell. 24,  2319-2327

J. Snyder, R.Y. Samson, S. Brumfield, S.D. Bell and M. Young. (2013) “Functional interplay between a virus and the ESCRT machinery in Archaea” PNAS, 110, 10783-10787

R.Y. Samson, T. Obita P. L-G Chong, R.L. Williams and S.D. Bell (2011) “Molecular and structural basis of ESCRT-III recruitment to membranes during archaeal cell division” Molecular Cell, 41, 186-196

R.Y. Samson, T. Obita, S.M. Freund, R.L. Williams and S.D. Bell (2008) “A role for the ESCRT system in cell division in Archaea” Science 322, 1710-1713