N-terminal α7 deletion of the proteasome 20S core particle substitutes for yeast PI31 function.

ABSTRACT: The proteasome core particle (CP) is a conserved protease complex that is formed by the stacking of two outer α-rings and two inner β-rings. The α-ring is a heteroheptameric ring of subunits α1 to α7 and acts as a gate that restricts entry of substrate proteins into the catalytic cavity formed by the two abutting β-rings. The 31-kDa proteasome inhibitor (PI31) was originally identified as a protein that binds to the CP and inhibits CP activity in vitro, but accumulating evidence indicates that PI31 is required for physiological proteasome activity. To clarify the in vivo role of PI31, we examined the Saccharomyces cerevisiae PI31 ortholog Fub1. Fub1 was essential in a situation where the CP assembly chaperone Pba4 was deleted. The lethality of Δfub1 Δpba4 was suppressed by deletion of the

SUBMITTER: Yashiroda H 

PROVIDER: S-EPMC4295373 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature