Biological process

down regulation of proteasomal ubiquitin-dependent protein catabolic process, down-regulation of proteasomal ubiquitin-dependent protein catabolic process, downregulation of proteasomal ubiquitin-dependent protein catabolic process

Any process that stops, prevents, or reduces the frequency, rate or extent of the breakdown of a protein or peptide by hydrolysis of its peptide bonds, initiated by the covalent attachment of ubiquitin, and mediated by the proteasome.