Dataset Information


Dissecting beta-ring assembly pathway of the mammalian 20S proteasome.

ABSTRACT: The 20S proteasome is the catalytic core of the 26S proteasome. It comprises four stacked rings of seven subunits each, alpha(1-7)beta(1-7)beta(1-7)alpha(1-7). Recent studies indicated that proteasome-specific chaperones and beta-subunit appendages assist in the formation of alpha-rings and dimerization of half-proteasomes, but the process involved in the assembly of beta-rings is poorly understood. Here, we clarify the mechanism of beta-ring formation on alpha-rings by characterizing assembly intermediates accumulated in cells depleted of each beta-subunit. Starting from beta2, incorporation of beta-subunits occurs in an orderly manner dependent on the propeptides of beta2 and beta5, and the C-terminal tail of beta2. Unexpectedly, hUmp1, a chaperone functioning at the final assembly step, is incorporated as early as beta2 and is required for the structural integrity of early assembly intermediates. We propose a model in which beta-ring formation is assisted by both intramolecular and extrinsic chaperones, whose roles are partially different between yeast and mammals.


PROVIDER: S-EPMC2519102 | BioStudies | 2008-01-01T00:00:00Z

REPOSITORIES: biostudies

Similar Datasets

1000-01-01 | S-EPMC1864979 | BioStudies
1000-01-01 | S-EPMC1171436 | BioStudies
2008-01-01 | S-EPMC2438424 | BioStudies
2015-01-01 | S-EPMC4677347 | BioStudies
2010-01-01 | S-EPMC2933030 | BioStudies
2018-01-01 | S-EPMC5899738 | BioStudies
1999-01-01 | S-EPMC34229 | BioStudies
| S-EPMC2748326 | BioStudies
| S-EPMC3037272 | BioStudies
2019-01-01 | S-EPMC6873196 | BioStudies