title: ARC3 is a stromal Z-ring accessory protein essential for plastid division.
abstract: In plants, chloroplast division is an integral part of development, and these vital organelles arise by binary fission from pre-existing cytosolic plastids. Chloroplasts arose by endosymbiosis and although they have retained elements of the bacterial cell division machinery to execute plastid division, they have evolved to require two functionally distinct forms of the FtsZ protein and have lost elements of the Min machinery required for Z-ring placement. Here, we analyse the plastid division component accumulation and replication of chloroplasts 3 (ARC3) and show that ARC3 forms part of the stromal plastid division machinery. ARC3 interacts specifically with AtFtsZ1, acting as a Z-ring accessory protein and defining a unique function for this family of FtsZ proteins. ARC3 is involved in division site placement, suggesting that it might functionally replace MinC, representing an important advance in our understanding of the mechanism of chloroplast division and the evolution of the chloroplast division machinery.
authors.affiliation: Center for Organelle Research, Department of Mathematics and Natural Science, University of Stavanger, Stavanger 4036, Norway.
authors.forename: Jodi
authors.initials: J
authors.lastname: Maple
authors.forename: Lea
authors.initials: L
authors.lastname: Vojta
authors.forename: Jurgen
authors.initials: J
authors.lastname: Soll
authors.forename: Simon G
authors.initials: SG
authors.lastname: Møller
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000502:physiology*; D003001:Cloning, Molecular; D017931:DNA Primers; D008856:Microscopy, Fluorescence; D018532:Pisum sativum; D010940:Plant Proteins / Q000378:metabolism; D014026:Nicotiana; D020798:Two-Hybrid System Techniques
chemical_list: C493630:ARC3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D017931:DNA Primers; C095113:FTSZ protein, Arabidopsis; D010940:Plant Proteins