Professor Ken Yokoyama

Area and Subject Taught Membrane Bioenergetics
Research Theme(s) (1) Molecular mechanism of energy conversion enzymes
(2) Studies of relationship between energy metabolism and cellular aging
Academic Degrees Doctor of Science, Tokyo Institute of Technology
Keywords for Research Field ATP, V-ATPase, Rotary motor, aging
Office Phone Number 81-75-705-3043

Research Overview

The focus of our laboratory is on both understanding molecular mechanism of energy conversion enzymes and relationship between energy metabolism and aging/longevity. The role of energy is fundamental to central phenomenon of organisms, e.g., growth, development, metabolism, and aging. Life is dependent on energy transformations; living organisms survive because of exchange of energy within and without. In all living organisms, adenosine 5’-triphosphate (ATP) is used as a ubiquitous energy currency, as well as an intra- and extra-cellular signaling molecule. ATP is predominantly generated by oxidative phosphorylation in mitochondria, in which respiratory complex I to V exist. Complex V, termed as ATP synthase, is a rotary molecular motor which converts chemical energy to rotation of central shaft apparatus, vice versa. Our focus is both on understanding detailed structure of complex I and an energy conversion mechanism of rotary molecular motor. We hope to know how these enzymes convert chemical energy to rotation of shaft or vectorial ion transport across the membranes. On the other hand, bioenergetics is deeply related on aging. Some mutants of respiratory enzymes in mitochondria increase the life span in some animals, such as nematodes and fl ies. We have started the studies on relationship between energy metabolism and aging using bio-imaging technique for ATP in nematode, Caenorhabditis elegans.

Notable Publications and Works in the Last Three Years

  1. Nakanishi A, Kishikawa J, Tamakoshi M, Mitsuoka K, and Yokoyama K. Cryo EM structure of intact rotary H+-ATPase/synthase from Thermus thermophilus. Nature Communications 9, Article number: 89 (2018) doi:10.1038/s41467-017-02553-6
  2. Kishikawa J, Inoue Y, Fujikawa M, Nishimura K, Nakanishi A, Tanabe T,
    Imamura H , Yokoyama K General anesthetics cause mitochondrial dysfunction and reduction of intracellular ATP levels PLOS ONE (2018)
  3. Baba M., Iwamoto K., Iino R, Ueno H., Hara M, Nakanishi A, Kishikawa J, Noji H., and *Yokoyama K. Rotation of artificial rotor axles in rotary molecular motors. Proc Nat Aca Sci USA 11214-11219 (2016)
  4. Hauer F, *Gerle C, Fischer N, Oshima A, Shinzawa-Itoh K, Shimada S, Yokoyama K, Fujiyoshi Y, *Stark H. GraDeR: Membrane Protein Complex Preparation for Single-Particle Cryo-EM. Structure 23, 1769-1775 (2015) (査読有り)
  5. Nakanishi A, Kishikawa J, Tamakoshi M, *Yokoyama K. The Ingenious Structure of Central Rotor Apparatus in VoV1; Key for Both Complex Disassembly and Energy Coupling between V1 and Vo. PLoS One. 10, e0119602. (2015)