title: Single particle tracking analysis of the chloroplast division protein FtsZ anchoring to the inner envelope membrane.
abstract: Replication of chloroplast in plant cells is an essential process that requires co-assembly of the tubulin-like plastid division proteins FtsZ1 and FtsZ2 at mid-chloroplast to form a ring structure called the Z-ring. The Z-ring is stabilized via its interaction with the transmembrane protein ARC6 on the inner envelope membrane of chloroplasts. Plants lacking ARC6 are defective in plastid division and contain only one or two enlarged chloroplasts per cell with abnormal localization of FtsZ: instead of a single Z-ring, many short FtsZ filaments are distributed throughout the chloroplast. ARC6 is thought to be the anchoring point for FtsZ assemblies. To investigate the role of ARC6 in FtsZ anchoring, the mobility of green fluorescent protein-tagged FtsZ assemblies was assessed by single particle tracking in mutant plants lacking the ARC6 protein. Mean square displacement analysis showed that the mobility of FtsZ assemblies is to a large extent characterized by anomalous diffusion behavior (indicative of intermittent binding) and restricted diffusion suggesting that besides ARC6-mediated anchoring, an additional FtsZ-anchoring mechanism is present in chloroplasts.
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Carol B
authors.initials: CB
authors.lastname: Johnson
authors.forename: Leung K
authors.initials: LK
authors.lastname: Tang
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Smith
authors.forename: Akshaya
authors.initials: A
authors.lastname: Ravichandran
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Luo
authors.forename: Stanislav
authors.initials: S
authors.lastname: Vitha
authors.forename: Andreas
authors.initials: A
authors.lastname: Holzenburg
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000378:metabolism*; D060365:Chloroplast Proteins / Q000378:metabolism*; D002736:Chloroplasts / Q000502:physiology*; D004261:DNA Replication; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D025941:Protein Interaction Mapping; D013194:Staining and Labeling / Q000379:methods
chemical_list: C502272:ARC6 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; C095113:FTSZ protein, Arabidopsis; D049452:Green Fluorescent Proteins