. "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." . . . . . "negative regulation of proteasomal ubiquitin-dependent protein catabolic 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" . "inhibition of proteasomal ubiquitin-dependent protein catabolic process" . . . . .