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.
Applied Biosystems - More Veriti

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 4 March 2005:
Vol. 307. no. 5714, pp. 1472 - 1476
DOI: 10.1126/science.1107710

Reports

OSBP Is a Cholesterol-Regulated Scaffolding Protein in Control of ERK1/2 Activation

Ping-yuan Wang, Jian Weng, Richard G. W. Anderson*

Oxysterol-binding protein (OSBP) is the founding member of a family of sterol-binding proteins implicated in vesicle transport, lipid metabolism, and signal transduction. Here, OSBP was found to function as a cholesterol-binding scaffolding protein coordinating the activity of two phosphatases to control the extracellular signal–regulated kinase (ERK) signaling pathway. Cytosolic OSBP formed a ~440-kilodalton oligomer with a member of the PTPPBS family of tyrosine phosphatases, the serine/threonine phosphatase PP2A, and cholesterol. This oligomer had dual specific phosphatase activity for phosphorylated ERK (pERK). When cell cholesterol was lowered, the oligomer disassembled and the level of pERK rose. The oligomer also disassembled when exposed to oxysterols. Increasing the amount of OSBP oligomer rendered cells resistant to the effects of cholesterol depletion and decreased the basal level of pERK. Thus, cholesterol functions through its interaction with OSBP outside of membranes to regulate the assembly of an oligomeric phosphatase that controls a key signaling pathway in the cell.

Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390–9039, USA.

* To whom correspondence should be addressed. E-mail: richard.anderson{at}utsouthwestern.edu

Read the Full Text






ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products


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