title: Functional Analysis of the Chloroplast Division Complex Using Schizosaccharomyces pombe as a Heterologous Expression System.
abstract: Chloroplast division is driven by a macromolecular complex that assembles at the midplastid. The FtsZ ring (Z ring) is the central structure in this complex, and is composed of the functionally distinct cytoskeletal proteins FtsZ1 and FtsZ2. Recent studies in the heterologous Schizosaccharomyces pombe system showed that Arabidopsis FtsZ1 and FtsZ2 filaments have distinct assembly and turnover characteristics. To further analyze these FtsZs, we employed this system to compare the assembly and dynamic properties of FtsZ1 and FtsZ2 lacking their N- and/or C-termini with those of their full-length counterparts. Our data provide evidence that the N-terminus of FtsZ2 is critical for its structural dominance over FtsZ1, and that the N- and C-termini promote polymer bundling and turnover of both FtsZs and contribute to their distinct behaviors. We also assessed how ARC6 affects FtsZ2 filament dynamics, and found that it interacts with and stabilizes FtsZ2 filaments in S. pombe independent of its presumed Z-ring tethering function in planta. Finally, we generated FtsZ1-FtsZ2 coexpression constructs to facilitate reconstitution of more complex interaction networks. Our experiments yield new insight into factors influencing FtsZ behavior and highlight the utility of S. pombe for analyzing chloroplast FtsZs and their assembly regulators.
authors.affiliation: 1Biochemistry and Molecular Biology Graduate Program,Michigan State University,East Lansing,MI 48824,USA.
authors.forename: Allan D
authors.initials: AD
authors.lastname: TerBush
authors.affiliation: 3Biochemistry and Molecular Biology Undergraduate Program,Michigan State University,East Lansing,MI 48824,USA.
authors.forename: Chris A
authors.initials: CA
authors.lastname: Porzondek
authors.affiliation: 2Department of Plant Biology,Michigan State University,East Lansing,MI 48824,USA.
authors.forename: Katherine W
authors.initials: KW
authors.lastname: Osteryoung
mesh_terms: D017360:Arabidopsis / Q000648:ultrastructure*; D029681:Arabidopsis Proteins / Q000378:metabolism; D002736:Chloroplasts / Q000648:ultrastructure*; D015870:Gene Expression; D001678:Organelle Biogenesis; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000378:metabolism; D012568:Schizosaccharomyces / Q000648:ultrastructure*
chemical_list: C502272:ARC6 protein, Arabidopsis; D029681:Arabidopsis Proteins; C095113:FTSZ protein, Arabidopsis; C523306:FtsZ1 protein, Arabidopsis; D011994:Recombinant Proteins
keywords: FtsZ; chloroplast division; fission yeast; fluorescence microscopy; fluorescence recovery after photobleaching