Direct Imaging of Intracellular Signaling Components That Regulate Bacterial Chemotaxis

Sci. Signal., 1 April 2014
Vol. 7, Issue 319, p. ra32
DOI: 10.1126/scisignal.2004963

Direct Imaging of Intracellular Signaling Components That Regulate Bacterial Chemotaxis

  1. Hajime Fukuoka1,2,
  2. Takashi Sagawa2,
  3. Yuichi Inoue1,2,
  4. Hiroto Takahashi1, and
  5. Akihiko Ishijima1,2,*
  1. 1Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai 980-8577, Japan.
  2. 2Graduate School of Life Sciences, Tohoku University, Aobak-ku, Sendai 980-8577, Japan.
  1. *Corresponding author. E-mail: ishijima{at}tagen.tohoku.ac.jp

Abstract

The bacterial chemotaxis system regulates the rotational direction of flagellar motors through an intracellular signaling molecule, the phosphorylated form of CheY (CheY-P). The binding of CheY-P to a motor is believed to switch the motor’s rotational direction from counterclockwise to clockwise. We demonstrated that the rotational switch of a motor was directly regulated by the binding and dissociation of CheY-P by simultaneously visualizing CheY tagged with green fluorescent protein and the rotational switching of a motor in live cells. The binding of 13 ± 7 CheY-P molecules was sufficient to induce clockwise rotation, and CheY-P molecules bound to and dissociated from a motor within ~100 ms during switching. Thus, we have directly measured the regulation of the output from a signal transduction pathway by intracellular signaling proteins.

Citation:

H. Fukuoka, T. Sagawa, Y. Inoue, H. Takahashi, and A. Ishijima, Direct Imaging of Intracellular Signaling Components That Regulate Bacterial Chemotaxis. Sci. Signal. 7, ra32 (2014).
Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882