Abstract
The Saccharomyces cerevisiae genes RAD23 and DDI1 were identified in a screen for multicopy suppressors of the temperature-sensitivity of a mutant allele of S. cerevisiae PDS1. Pds1 is a regulator of anaphase that needs to accumulate and then be degraded by the ubiquitin-proteasome pathway at the metaphase-anaphase transition for cells to progress normally through mitosis. Both the Rad23 and Ddi1 pds1 suppression phenotypes depend on a shared motif known as a UBA domain found in a variety of proteins associated with ubiquitin metabolism. UBA domains were found to be essential for homodimerization of Rad23 and heterodimerization between Rad23 and Ddi1, but not for homodimerization of Ddi1. This observation, coupled with the findings that Rad23 and Ddi1 UBA domains bind ubiquitin and that dimerization of Rad23 blocks ubiquitin binding, suggests a possible mechanism for regulating Rad23 and Ddi1 function.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 955-963 |
| Number of pages | 9 |
| Journal | Journal of Molecular Biology |
| Volume | 313 |
| Issue number | 5 |
| DOIs | |
| State | Published - Nov 9 2001 |
Bibliographical note
Funding Information:B.L.B. was supported by both NIH and University of California Office of the President fellowships. D.J.C. was supported by both EMBO and DOD Breast Cancer Research Program fellowships. The Reed laboratory is supported, in part, by NIH grants GM38328 and CA85487. We thank L. Prakash for the α-Rad23 antibody, E. Komives for help in rendering the ribbon diagram for the HHR23A UBA2 NMR structure and F. Simeoni for help in performing the cross-linking experiments. We thank the members of the Reed laboratory and the Scripps Cell Cycle groups for helpful discussions, and specifically John Tainer for use of his laboratory and computing facilities.
Keywords
- DNA damage
- Interaction domain
- Rad23
- UBA domain
- Ubiquitin