. "Any process that activates or increases the frequency, rate or extent of the addition of ubiquitin groups to a protein." . . . "positive regulation of protein ubiquitination" . "activation of protein ubiquitination" . "stimulation of protein ubiquitination" . "up regulation of protein ubiquitination" . "up-regulation of protein ubiquitination" . "upregulation of protein ubiquitination" . . . . . .