Functional characterization of rpn3 uncovers a distinct 19S proteasomal subunit requirement for ubiquitin-dependent proteolysis of cell cycle regulatory proteins in budding yeast.

ABSTRACT: By selectively eliminating ubiquitin-conjugated proteins, the 26S proteasome plays a pivotal role in a large variety of cellular regulatory processes, particularly in the control of cell cycle transitions. Access of ubiquitinated substrates to the inner catalytic chamber within the 20S core particle is mediated by the 19S regulatory particle (RP), whose subunit composition in budding yeast has been recently elucidated. In this study, we have investigated the cell cycle defects resulting from conditional inactivation of one of these RP components, the essential non-ATPase Rpn3/Sun2 subunit. Using temperature-sensitive mutant alleles, we show that rpn3 mutations do not prevent the G(1)/S transition but cause a metaphase arrest, indicating that the essential Rpn3 function is limiting for mito

SUBMITTER: Bailly E 

PROVIDER: S-EPMC84683 | biostudies-literature | 1999 Oct

REPOSITORIES: biostudies-literature