Related Experiment Video
Updated: Aug 16, 2026

Measuring Composition of CD95 Death-Inducing Signaling Complex and Processing of Procaspase-8 in this Complex
Published on: August 2, 2021
The co-chaperone p23 is degraded by caspases and the proteasome during apoptosis
Jens Mollerup1, Martin W Berchtold
1Institute of Molecular Biology and Physiology, Department of Molecular Cell Biology, University of Copenhagen, Oester Farimagsgade 2A, 1353 Copenhagen K, Denmark. jmollerup@my.molbio.ku.dk
Abstract:
The heat shock protein 90 co-chaperone p23 has recently been shown to be up-regulated in cancer cells and down-regulated in atheroschlerotic plaques. We found that p23 is degraded during apoptosis induced by several stimuli, including Fas and TNFalpha-receptor activation as well as staurosporine treatment. Caspase inhibition protected p23 from degradation in several cell lines. In addition, recombinant caspase-3 and 8 cleaved p23 at Asp 142 generating a degradation product of 18 kDa as seen in apoptotic cells. Truncated p23 is further degraded in a proteasome dependent process during apoptosis. Furthermore, we found that the anti-aggregating activity of truncated p23 was reduced compared to full length p23 indicating that caspase mediated p23 degradation contributes to protein destabilisation in apoptosis.
Related Concept Videos
Caspases
The Intrinsic Apoptotic Pathway
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
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...
Molecular Chaperones and Protein Folding
The...
Molecular Chaperones and Protein Folding
The...

