title: Isolated chloroplast division machinery can actively constrict after stretching.
abstract: Chloroplast division involves plastid-dividing, dynamin, and FtsZ (PDF) rings. We isolated intact supertwisted (or spiral) and circular PDF machineries from chloroplasts of the red alga Cyanidioschyzon merolae. After individual intact PDF machineries were stretched to four times their original lengths with optical tweezers, they spontaneously returned to their original sizes. Dynamin-released PDF machineries did not retain the spiral structure and could not be stretched. Thus, dynamin may generate the motive force for contraction by filament sliding in dividing chloroplasts, in addition to pinching-off the membranes.
authors.affiliation: Laboratory of Cell Biology, Department of Life Science, College of Science, Rikkyo (St. Paul's) University, Toshima, Tokyo 171-8501, Japan.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Haruko
authors.initials: H
authors.lastname: Kuroiwa
authors.forename: Osami
authors.initials: O
authors.lastname: Misumi
authors.forename: Keiji
authors.initials: K
authors.lastname: Nishida
authors.forename: Fumi
authors.initials: F
authors.lastname: Yagisawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nanamiya
authors.forename: Fujio
authors.initials: F
authors.lastname: Kawamura
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Kuroiwa
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology* / Q000648:ultrastructure; D020418:Algal Proteins / Q000502:physiology*; D002736:Chloroplasts / Q000502:physiology* / Q000648:ultrastructure; D034281:Dynamins / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000502:physiology; D007425:Intracellular Membranes / Q000502:physiology / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D000461:Rhodophyta / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D020418:Algal Proteins; D020558:GTP Phosphohydrolases; D034281:Dynamins