Model for Ub^ext affects on toxic protein aggregates.

<p>We propose that enhanced protein aggregate toxicity in Ub^ext-expressing cells is due to the inability of misfolded amyloidogenic proteins to be properly sequestered. The small soluble oligomers are more toxic than the large insoluble protein aggregates. UPS impairment caused by the expression of Ub^ext may hinder the rapid sequestration or retention of toxic oligomers into large protein aggregates.