New work from the lab of Daniel Finley, HMS professor of cell biology, has teased out in exquisite detail how helper proteins assemble the barrel of a proteasome, a large protein complex that acts like a cell’s garbage disposal by grabbing onto excess and damaged proteins and degrading them.

The helpers build the ring-shaped assembly piece by piece from smaller proteins in a precise order, with each helper ensuring that its piece clicks in at exactly the right moment. This is a novel type of assembly process that had, until now, been difficult to study because the proteasome assembles so rapidly—in a matter of minutes. In addition, the team found that one of the helper proteins is produced by a known oncogene, a gene that turns a cell cancerous when mutated or overexpressed. This discovery may also influence cancer research since many anticancer drugs prevent proteasomes from forming or functioning. For details, see two companion studies by first authors Jeroen Roelofs and Soyeon Park published in the June 11 Nature.

Students may contact Daniel Finley at Daniel_finley@hms.harvard.edu for more information.

Conflict Disclosure: The authors report no conflicts.

Funding Sources: The National Institutes of Health supported this work. Soyeon Park received an NIH NRSA fellowship, and Jeroen Roelofs received an EMBO long-term fellowship; the content of the work is the responsibility solely of the authors.