Phototactic and chemotactic signal transduction by transmembrane receptors and transducers in microorganisms.
Microorganisms show attractant and repellent responses to survive in the various environments in which they live. Those phototaxic (to light) and chemotaxic (to chemicals) responses are regulated by membrane-embedded receptors and transducers. This article reviews the following: (1) the signal relay mechanisms by two photoreceptors, Sensory Rhodopsin I (SRI) and Sensory Rhodopsin II (SRII) and their transducers (HtrI and HtrII) responsible for phototaxis in microorganisms; and (2) the signal relay mechanism of a chemoreceptor/transducer protein, Tar, responsible for chemotaxis in E. coli. Based on results mainly obtained by our group together with other findings, the possible molecular mechanisms for phototaxis and chemotaxis are discussed.
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan. 4dsksuzu@bunshi4.bio.nagoya-u.ac.jp
Daisuke
D
Suzuki
Hiroki
H
Irieda
Michio
M
Homma
Ikuro
I
Kawagishi
Yuki
Y
Sudo
D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D001436:Bacteriorhodopsins / Q000302:isolation & purification / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D002352:Carrier Proteins / Q000378:metabolism; D002633:Chemotaxis; D004926:Escherichia coli / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D011487:Protein Conformation; D025603:Sensory Rhodopsins / Q000737:chemistry*; D015398:Signal Transduction
D001426:Bacterial Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D025603:Sensory Rhodopsins; D001436:Bacteriorhodopsins