title: Chara myosin and the energy of cytoplasmic streaming.
abstract: Recently, it was found that myosin generating very fast cytoplasmic streaming in Chara corallina has very high ATPase activity. To estimate the energy consumed by this myosin, its concentration in the internodal cells of C. corallina was determined by quantitative immunoblot. It was found that the concentration of Chara myosin was considerably high (200 nM) and the amount of ATP consumed by this myosin would exceed that supplied by dark respiration if all myosin molecules were fully activated by the interaction with actin. These results and model calculations suggested that the energy required to generate cytoplasmic streaming is very small and only one-hundredth of the existing myosin is enough to maintain the force for the streaming in the Chara cell.
authors.affiliation: Department of Biology, Chiba University, Inage-ku, Chiba, 263-8522 Japan. yamamoto@bio.s.chiba-u.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Kiyo
authors.initials: K
authors.lastname: Shimada
authors.forename: Khoji
authors.initials: K
authors.lastname: Ito
authors.forename: Saeko
authors.initials: S
authors.lastname: Hamada
authors.forename: Akio
authors.initials: A
authors.lastname: Ishijima
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Masashi
authors.initials: M
authors.lastname: Tazawa
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D044784:Chara / Q000166:cytology / Q000378:metabolism*; D003595:Cytoplasmic Streaming; D015151:Immunoblotting; D007700:Kinetics; D009218:Myosins / Q000378:metabolism*
chemical_list: D000251:Adenosine Triphosphatases; D009218:Myosins