Discovery of the Motor Mechanism of “Myosin V,” a Motor Protein “Transporter-in-a-cell” that Walks Bipedally

October 18(Wed), 2017

Tomonari Sumi, Associate Professor at the Research Institute for Interdisciplinary Science, Okayama University, revealed the motor mechanism of “myosin V (Figure 1),” which is a motor protein “transporter-in-a-cell,” using the mathematical model of single-molecule experimental data (Figure 2). This research result was published in Scientific Reports, a U.K. scientific magazine on October 18th at 10:00 am local time (6:00 pm Japan time).

Myosins are well known as motor proteins for their role in muscle contraction and relaxation, using the chemical reaction energy of adenosine triphosphate (“ATP”) that is often referred to as a “molecular unit of currency”.  On the other hand, myosin V is a molecular motor (Figure 1) that “walks bipedally” and transports mRNA and vesicle within the actin-rich periphery of cells. Although myosin-V’s  motor properties have been extensively investigated by single-molecule experiments, the chemomechanical coupling mechanism has been controversial and many possible stochastic models have been proposed. Based on the “design principle” of two-headed molecule motors that he discovered in his previous research on kinesin, Dr. Sumi revealed the mechanism by which both the “chemomechanical coupling” and “clutch function” are compatible, which corresponds to the relationship between an engine and a transmission in an automobile.

This research result will provide important knowledge for unified understanding of the chemomechanical coupling mechanism and the energy conversion efficiencies of various molecule motors in cells.

Article Information

DOI: 10.1038/s41598-017-13661-0

Journal: Scientific Reports 

Title: Myosin V: Chemomechanical-coupling ratchet with load-induced mechanical slip

Authors: Tomonari Sumi

Year of Publication: 2017


Okayama University Silicon Valley Office (OUSVO)

Contact: Mototaka Senda, Ph.D.

Phone:    (1)510-894-3067


Myosin V, adenosine triphosphate , ATP,

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