A breakthrough in understanding cellular protein destruction

A team of researchers at the Lawrence Berkeley National Laboratory and the University of California, Berkeley have provided the most detailed look ever at proteasomes, regulatory particles that are a crucial part of human cells’ protein machines. At any given moment, a human cell contains about 100,000 different proteins, with proteins being continuously manufactured and destroyed as needed to keep the cell healthy. Unwanted proteins are labeled for elimination with a polypeptide called ubiquitin. A protein marked with ubiquitin is delivered to any one of the some 30,000 proteasomes in the cell which degrade the protein. The activities controlled by this regulatory particle are critical to the quality control of cellular proteins, as well as a broad range of vital biochemical processes, including transcription, DNA repair and immune defenses.