Chloroplast FtsZ assembles into a contractible ring via tubulin-like heteropolymerization.
Chloroplast division is driven by a ring containing FtsZ1 and FtsZ2 proteins, which originated from bacterial FtsZ, a tubulin-like protein; however, mechanistic details of the chloroplast FtsZ ring remain unclear. Here, we report that FtsZ1 and FtsZ2 can heteropolymerize into a contractible ring ex vivo. Fluorescently labelled FtsZ1 and/or FtsZ2 formed single rings in cells of the yeast Pichia pastoris. Photobleaching experiments indicated that co-assembly of FtsZ1 and FtsZ2 imparts polarity to polymerization. Assembly of FtsZ chimaeras revealed that the protofilaments assemble via heteropolymerization of FtsZ2 and FtsZ1. Contraction of the ring was accompanied by an increase in the filament turnover rate. Our findings suggest that the evolutionary duplication of FtsZ in plants may have increased the mobility and kinetics of FtsZ ring dynamics in chloroplast division. Thus, the gene duplication and heteropolymerization of chloroplast FtsZs may represent convergent evolution with eukaryotic tubulin.
Department of Plant Biology, Michigan State University, East Lansing 48824-1312, Michigan, USA.
Yamato
Y
Yoshida
Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yuko
Y
Mogi
Department of Plant Biology, Michigan State University, East Lansing 48824-1312, Michigan, USA.
Allan D
AD
TerBush
Department of Plant Biology, Michigan State University, East Lansing 48824-1312, Michigan, USA.
Katherine W
KW
Osteryoung
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D060365:Chloroplast Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030781:Organisms, Genetically Modified / Q000235:genetics; D010843:Pichia / Q000235:genetics; D058105:Polymerization
D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; C095113:FTSZ protein, Arabidopsis; C523306:FtsZ1 protein, Arabidopsis