Chloroplast Targeting of Chloroplast Division FtsZ2 Proteins in Arabidopsis

Fujiwara, Makoto; Yoshida, Shigeo

doi:10.1006/bbrc.2001.5588

Cited by 42 publications

(27 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…OM and IM, outer and inner envelope membranes, respectively. nance, because FtsZ1, FtsZ2, MinD, and MinE also are localized in the stroma (Osteryoung and Vierling, 1995;Colletti et al, 2000;Fujiwara and Yoshida, 2001;Itoh et al, 2001;McAndrew et al, 2001;Maple et al, 2002). Future experiments with chloroplasts from ARC6-GFP transgenic plants should further confirm the localization of GFP and the C terminus of ARC6 in the intermembrane space.…”

Section: Arc6 Localization and Membrane Topologymentioning

confidence: 88%

ARC6 Is a J-Domain Plastid Division Protein and an Evolutionary Descendant of the Cyanobacterial Cell Division Protein Ftn2[W]

et al. 2003

View full text Add to dashboard Cite

Replication of chloroplasts is essential for achieving and maintaining optimal plastid numbers in plant cells. The plastid division machinery contains components of both endosymbiotic and host cell origin, but little is known about the regulation and molecular mechanisms that govern the division process. The Arabidopsis mutant arc6 is defective in plastid division, and its leaf mesophyll cells contain only one or two grossly enlarged chloroplasts. We show here that arc6 chloroplasts also exhibit abnormal localization of the key plastid division proteins FtsZ1 and FtsZ2. Whereas in wild-type plants, the FtsZ proteins assemble into a ring at the plastid division site, chloroplasts in the arc6 mutant contain numerous short, disorganized FtsZ filament fragments. We identified the mutation in arc6 and show that the ARC6 gene encodes a chloroplast-targeted DnaJ-like protein localized to the plastid envelope membrane. An ARC6-green fluorescent protein fusion protein was localized to a ring at the center of the chloroplasts and rescued the chloroplast division defect in the arc6 mutant. The ARC6 gene product is related closely to Ftn2, a prokaryotic cell division protein unique to cyanobacteria. Based on the FtsZ filament morphology observed in the arc6 mutant and in plants that overexpress ARC6 , we hypothesize that ARC6 functions in the assembly and/or stabilization of the plastid-dividing FtsZ ring. We also analyzed FtsZ localization patterns in transgenic plants in which plastid division was blocked by altered expression of the division site-determining factor AtMinD. Our results indicate that MinD and ARC6 act in opposite directions: ARC6 promotes and MinD inhibits FtsZ filament formation in the chloroplast.

show abstract

Section: Arc6 Localization and Membrane Topologymentioning

confidence: 88%

ARC6 Is a J-Domain Plastid Division Protein and an Evolutionary Descendant of the Cyanobacterial Cell Division Protein Ftn2[W]

et al. 2003

View full text Add to dashboard Cite

show abstract

“…However, mitochondrial and chloroplast division are not equivalent processes. Chloroplast division requires the activity of several prokaryotically derived proteins in the chloroplast stroma, including FtsZ1, FtsZ2, MinD, MinE, and ARTEMIS (6,7,(11)(12)(13)(14)49), whereas related molecules are lacking in the mitochondria of animals, plants, and fungi, and no matrix-localized mitochondrial division proteins have been identified in these organisms.…”

Section: Discussionmentioning

confidence: 99%

ARC5, a cytosolic dynamin-like protein from plants, is part of the chloroplast division machinery

Gao

Kadirjan-Kalbach

Froehlich

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

253

254

View full text Add to dashboard Cite

Chloroplast division in plant cells is orchestrated by a complex macromolecular machine with components positioned on both the inner and outer envelope surfaces. The only plastid division proteins identified to date are of endosymbiotic origin and are localized inside the organelle. Employing positional cloning methods in Arabidopsis in conjunction with a novel strategy for pinpointing the mutant locus, we have identified a gene encoding a new chloroplast division protein, ARC5. Mutants of ARC5 exhibit defects in chloroplast constriction, have enlarged, dumbbellshaped chloroplasts, and are rescued by a wild-type copy of ARC5. The ARC5 gene product shares similarity with the dynamin family of GTPases, which mediate endocytosis, mitochondrial division, and other organellar fission and fusion events in eukaryotes. Phylogenetic analysis showed that ARC5 is related to a group of dynamin-like proteins unique to plants. A GFP-ARC5 fusion protein localizes to a ring at the chloroplast division site. Chloroplast import and protease protection assays indicate that the ARC5 ring is positioned on the outer surface of the chloroplast. Thus, ARC5 is the first cytosolic component of the chloroplast division complex to be identified. ARC5 has no obvious counterparts in prokaryotes, suggesting that it evolved from a dynamin-related protein present in the eukaryotic ancestor of plants. These results indicate that the chloroplast division apparatus is of mixed evolutionary origin and that it shares structural and mechanistic similarities with both the cell division machinery of bacteria and the dynamin-mediated organellar fission machineries of eukaryotes.T he chloroplasts of plants and algae are widely believed to have evolved only once from a free-living cyanobacterial endosymbiont (1). Over evolutionary time, many of the genes once present in the endosymbiont have been transferred to the nuclear genome where they have acquired sequences encoding transit peptides that direct their gene products back to the chloroplast (1, 2). This scenario describes the origin of the five previously identified plastid division proteins in plants, all of which evolved from related cell division proteins in cyanobacteria, are encoded in the nucleus, and are localized inside the chloroplast. These include FtsZ1 and FtsZ2, tubulin-like proteins that localize to a ring at the site of plastid constriction (3-10), MinD and MinE, which regulate placement of the plastid division site (11-13), and ARTEMIS, which appears to mediate constriction of the envelope membranes (14).Despite localization of the previously identified plastid division proteins inside the chloroplasts in plant cells, ultrastructural studies have shown that plastid division entails the coordinated activity of components localized outside as well as inside the organelle. In plants, the chloroplast division complex comprises electron-dense structures situated both on the stromal surface of the inner envelope membrane and on the cytosolic surface of the outer membrane (15). These structur...

show abstract

“…FtsZ2 has been shown, by fluorescent and electron microscopy, to be present in the chloroplast stroma in lily (Mori et al 2001), and to localize at the chloroplast midpoint in Arabidopsis (Vitha et al 2001). In vivo experiments with fusion proteins in which the putative transit peptide of both Arabidopsis FtsZ2 forms were fused to the green fluorescent protein (GFP) have confirmed that these sequences function as chloroplast-targeting signals (Fujiwara and Yoshida 2001). That FtsZ proteins are involved in chloroplast division has been demonstrated in the moss Physcomitrella patens by knockout of the gene (Strepp et al 1998) and in A. thaliana by antisense expression of the FtsZ genes (Osteryoung et al 1998).…”

Section: Introductionmentioning

confidence: 95%

Cell cycle-dependent modulation of FtsZ expression in synchronized tobacco BY2 cells

et al. 2002

View full text Add to dashboard Cite

In higher plants, the FtsZ protein, the ancestor of tubulin, has been shown to be implicated in both proplastid division, which occurs in dividing cells and in the division of the differentiated plastids present in nondividing cells. Here we report studies on the expression of the two FtsZ gene families in higher plants, FtsZ1 and FtsZ2, in non-synchronized and synchronized tobacco BY2 cells. We have isolated and characterized members of each gene family from Nicotiana tabacum. Specific cDNA probes for each tobacco FtsZ gene family and polyclonal antibodies specific for the FtsZ1 and FtsZ2 proteins were obtained in order to determine mRNA and protein levels. A constant level of FtsZ1 and FtsZ2 transcripts and proteins was observed in non-synchronized cell cultures. However, a complex pattern of expression of both gene families was observed during the cell cycle in synchronized cells, with mRNA and protein levels peaking during cell division, thus implying that the FtsZ proteins may be involved in plastid transmission to the two daughter cells.

show abstract

Chloroplast Targeting of Chloroplast Division FtsZ2 Proteins in Arabidopsis

Cited by 42 publications

References 40 publications

ARC6 Is a J-Domain Plastid Division Protein and an Evolutionary Descendant of the Cyanobacterial Cell Division Protein Ftn2[W]

ARC6 Is a J-Domain Plastid Division Protein and an Evolutionary Descendant of the Cyanobacterial Cell Division Protein Ftn2[W]

ARC5, a cytosolic dynamin-like protein from plants, is part of the chloroplast division machinery

Cell cycle-dependent modulation of FtsZ expression in synchronized tobacco BY2 cells

Contact Info

Product

Resources

About