Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Career Basics

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 24 December 2004:
Vol. 306. no. 5705, pp. 2270 - 2272
DOI: 10.1126/science.1103996
Prev | Table of Contents | Next

Reports

Enterococcus faecalis Senses Target Cells and in Response Expresses Cytolysin

Phillip S. Coburn,1 Christopher M. Pillar,2* Bradley D. Jett,2{dagger} Wolfgang Haas,2{ddagger} Michael S. Gilmore1,2*§

Many virulent strains of Enterococcus faecalis produce a two-subunit toxin, termed cytolysin. Cytolysin expression is regulated by one of the subunits (CylLS'') through a quorum-sensing autoinduction mechanism. We found that when target cells are absent, the other subunit (CylLL'') forms a complex with CylLS'', blocking it from autoinducing the operon. When target cells are present, however, CylLL'' binds preferentially to the target, allowing free CylLS'' to accumulate above the induction threshold. Thus, enterococci use CylLL'' to actively probe the environment for target cells, and when target cells are detected, allows the organism to express high levels of cytolysin in response.

1 Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Stanton L. Young Biomedical Research Center, Room 356, Post Office Box 26901, Oklahoma City, OK 73190, USA.
2 Department of Ophthalmology, University of Oklahoma Health Sciences Center, Stanton L. Young Biomedical Research Center, Room 356, Post Office Box 26901, Oklahoma City, OK 73190, USA.


* Present address: Department of Ophthalmology, Harvard Medical School, and The Schepens Eye Research Institute, 20 Staniford Street, Boston, MA 02114, USA.

{dagger} Present address: Department of Biology, Oklahoma Baptist University, Shawnee, OK 74804, USA.

{ddagger} Present address: Center for Oral Biology, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA.

§ To whom correspondence should be addressed. E-mail: mgilmore{at}vision.eri.harvard.edu

Read the Full Text

ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)