Unravelling the atypical modes of cell division in Planctomycete bacteria: budding and FtsZ-less binary fission


The enigmatic planctomycetal cell is compartmentalized by either extensive invaginations of the cytoplasmic membrane or in anammox Planctomycetes by the presence of an energy-conserving intracytoplasmic compartment. The Planctomycete mode of cell division is atypical for bacteria: they divide either by FtsZ-less budding or FtsZ-less binary fission (anammox Planctomycetes). How these two cell division modes are organized in compartmentalized Planctomycete cells is entirely unknown. All Planctomycetes lack a substantial set of the known “essential” cell division genes including the important cell division protein FtsZ. Since only recently genetic tools were established for two budding Planctomycetes, functional characterization of specific proteins is unprecedented in these bacteria. The objective of this project is to elucidate the molecular and genetic mechanism of the atypical Planctomycete cell division. Based on preliminary experiments, we hypothesize a major role for the actin-homolog MreB. The budding Planctomycete Planctopirus limnophila and FtsZ-less binary fission anammox Planctomycete Kuenenia stuttgartiensis will be used as model systems. Candidate cell division proteins will be identified through several omics approaches. For P. limnophila, the location and function of candidate cell division proteins will be investigated by GFP-tagging and site-directed mutagenesis. For K. stuttgartiensis, the location and interaction of candidate cell division proteins will be investigated by immunolocalization and –precipitation. For both, different cell division phases will be examined through time-lapse microscopy and cryoelectron tomography and using inhibitor experiments we will focus specifically on the function of MreB. The results will add new insights to the fundaments of bacterial cell biology and Planctomycete applications.





Dr. L.A.M.P. van Niftrik

Verbonden aan

Radboud Universiteit Nijmegen, Faculteit der Natuurwetenschappen, Wiskunde en Informatica, Computer Science


01/09/2017 tot 31/08/2021


€ 368.974