Single molecule physiology, inner molecules, molecules and cells

2014 Fiscal Year Final Research Report

• Project/Area Number: 23247022
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Biophysics
• Research Institution: The University of Tokyo
• Principal Investigator: HIDEO Higuchi 東京大学, 理学(系)研究科(研究院), 教授 (90165093)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: ダイニン / 単頭 / 力 / 変位 / エンドサイトーシス / 1分子 / Tatペプチド

Outline of Final Research Achievements

We use optical trapping to show the single molecule properties and the effect of load on the mechanochemical cycle of the motor domain of human dynein. The double-headed motor domain is responsible for producing a high force of ~6 pN with a predominant step size of 8 nm. An unbinding force measurement indicates that dynein-microtubule binding is weak for the ADP-vanadate state and strong for the nucleotide-free, AMPPNP and ADP states. The unbinding force was weaker when dynein was pulled toward the minus end of microtubule. Our results suggest that force plays an important role in the mechanochemical cycle of dynein to ensure the increasing of a probability for rear-head detachment with strain.
We imaged the trafficking of PAR-1 carrying vesicles to analyze the movement of activated PAR-1 after internalization. By the triple-view method consisting of dual-focus fluorescence and phase contrast optics, we detected endocytosis quantum dots 3-dimensional with high special precision.

Free Research Field

生物物理学