Editors' ChoiceProtein Degradation

Polyubiquitination of p53 by p300

Science's STKE  15 Apr 2003:
Vol. 2003, Issue 178, pp. tw154
DOI: 10.1126/stke.2003.178.tw154

The transcription factor and tumor suppressor protein p53 undergoes rapid turnover in the cell by the ubiquitin-proteasome system. Not only is it monoubiquitinated, but p53 is modified by chains of ubiquitin molecules to ensure efficient degradation. Grossman et al. have determined that p53 is polyubiquitinated by p300, a transcriptional regulator. This enzymatic activity settles some of the outstanding riddles of how p300 can control both p53 activation and destruction. Because p300 regulates various short-lived transcription factors, the finding may have broader implications.

S. R. Grossman, M. E. Deato, C. Brignone, H. M. Chan, A. L. Kung, H. Tagami, Y. Nakatani, D. M. Livingston, Polyubiquitination of p53 by a ubiquitin ligase activity of p300. Science 300, 342-344 (2003). [Abstract] [Full Text]