High impact information on PRE4

• The deletion of 19 residues from the beta7/Pre4 C terminus leads to an accumulation of half-proteasome precursor complexes containing the maturation factor Ump1 [1].
• Our data obtained with yeast strains that expressed the mature form of Pre3 lacking its propeptide suggest that interactions between the Pre4 C terminus and Pre3 stabilize a conformation of its active site, which is essential for post-acidic activity [1].
• The PRE4 gene codes for a subunit of the yeast proteasome necessary for peptidylglutamyl-peptide-hydrolyzing activity. Mutations link the proteasome to stress- and ubiquitin-dependent proteolysis [2].
• Using one of these mutants (pre4-1), we cloned the PRE4 gene and uncovered an open reading frame with 266 amino acids coding for a predicted protein of 29.4 kDa [2].
• The Pre4 amino acid sequence shows strong homology to the beta-subunit of the Xenopus laevis proteasome [2].

Biological context of PRE4

• PRE4 is an essential gene encoding the beta-7 subunit of the 20S proteasome core [3].
• The generation of different, incompletely processed forms of the Pre4 precursor in active site mutants suggested that maturation of non-active proteasomal beta-type subunits is exerted by active subunits and occurs in the fully assembled particle [4].

Associations of PRE4 with chemical compounds

• Mutation of two potentially active site threonine residues in the Pre4 subunit excluded its catalytic involvement in any of the three peptidase activities [4].

Regulatory relationships of PRE4

• A Val-to-Phe substitution within a highly conserved region of Pre4p that disrupts proteasome function suppresses the growth arrest of RPM2-null cells on fermentable media [3].

References