Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Chemotactic signal integration in bacteria

S Khan1, J L Spudich, J A McCray

  • 1Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.

Proceedings of the National Academy of Sciences of the United States of America
|October 10, 1995
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Genomic perspective on the photobiology of Halobacterium species NRC-1, a phototrophic, phototactic, and UV-tolerant haloarchaeon.

Photosynthesis research·2005
Same author

Light-induced structural changes occur in the transmembrane helices of the Natronobacterium pharaonis HtrII transducer.

Biochemistry·2001
Same author

Molecular mechanism of spectral tuning in sensory rhodopsin II.

Biochemistry·2001
Same author

An archaeal photosignal-transducing module mediates phototaxis in Escherichia coli.

Journal of bacteriology·2001
Same author

Proteorhodopsin phototrophy in the ocean.

Nature·2001
Same author

Crystal structure of sensory rhodopsin II at 2.4 angstroms: insights into color tuning and transducer interaction.

Science (New York, N.Y.)·2001

Escherichia coli exhibits complex chemotactic signaling, integrating attractant and repellent signals differently based on receptor interactions. This research reveals how bacteria process dual inputs, influencing their movement towards favorable environments.

Area of Science:

  • Microbiology
  • Cellular Biology
  • Biophysics

Background:

  • Chemotaxis in Escherichia coli (E. coli) involves processing both attractant and repellent signals.
  • Understanding signal integration mechanisms is crucial for deciphering bacterial navigation.
  • Key receptors like Tar and Tsr mediate responses to amino acids and pH changes.

Purpose of the Study:

  • To investigate the mechanisms of chemotactic signal processing in E. coli under dual input conditions.
  • To analyze behavioral responses to simultaneous attractant and repellent stimuli.
  • To elucidate how different chemoreceptors (Tar and Tsr) contribute to integrated or non-integrated responses.

Main Methods:

  • Utilized photoactivable 'caged' compounds for precise stimulus delivery.

Related Experiment Videos

  • Employed computer video analysis to quantify bacterial behavioral responses.
  • Studied chemoreceptor deletion mutants (Tar deletion) alongside wild-type E. coli.

    • Main Results:

    • In Tar deletion mutants, simultaneous photorelease of protons (repellent) and serine (attractant) yielded a single response (tumbling or smooth-swimming) based on effector amounts.
    • Wild-type E. coli showed a biphasic response to proton release at neutral pH (tumbling then smooth-swimming), attributed to Tsr and Tar signaling.
    • At alkaline pH, the Tar-mediated smooth-swimming response dominated, diminishing the preceding Tsr-mediated tumbling response.

    Conclusions:

    • Individual receptors integrate multiple ligands, generating a single response.
    • Ligand binding to different receptors can lead to sequential, non-integrated responses (tumbling followed by smooth-swimming).
    • Varying signal intensities from different receptors can result in an integrated response, potentially aiding E. coli's migration towards neutral pH.