A chewing proteasome is stabilized

To do its job of degrading misfolded proteins, the proteasome's core particle (CP) and regulatory particle (RP) must link up. But what keeps them together while they work? According to new research by Maurits Kleijnen, Jeroen Roelofs, Daniel Finley (Harvard Medical School, Boston, MA), and colleagues, having something to chew on might keep the proteasome intact until the job is finished.

The proteasome's active sites sit deep within its core, far removed from its regulatory particles, which cap the ends of the proteolytic tunnel. Nonetheless, proteasome inhibitors that bind to the core's active site, such as epoxomicin, make it more likely that the core and regulatory units coprecipitate, suggesting that inhibitors may stabilize the interface between the...