Related Experiment Video
Updated: Aug 11, 2026

Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
Published on: May 18, 2009
The axial channel of the proteasome core particle is gated by the Rpt2 ATPase and controls both substrate entry and
A Köhler1, P Cascio, D S Leggett
1Department of Cell Biology, Harvard Medical School, 02115, Boston, MA, USA.
Abstract:
Substrates enter the proteasome core particle (CP) through a channel that opens upon association with the regulatory particle (RP). Using yeast mutants, we show that channel opening is mediated by the ATPase domain of Rpt2, one of six ATPases in the RP. To test whether degradation products exit through this channel, we analyzed their size distribution. Their median length from an open-channel CP mutant was 40% greater than that from the wild-type. Thus, channel opening may enhance the yield of peptides long enough to function in antigen presentation. These experiments demonstrate that gating of the RP channel controls both substrate entry and product release, and is specifically regulated by an ATPase in the base of the RP.
More Related Videos
09:57Examining Proteasome Assembly with Recombinant Archaeal Proteasomes and Nondenaturing PAGE: The Case for a Combined Approach
Published on: December 17, 2016
12:25Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
Published on: September 28, 2018
Related Concept Videos
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
The Proteasome Structure
The proteasome is an...