Figure 6.

Model for the role of PLIC-1 aggresome formation. (A) Under low levels of protein aggregation, the UBL domain of PLIC-1 shuttles ubiquitinated misfolded proteins to the proteasome through the UIM of S5a. (B) Under high levels, larger ubiquitinated aggregates overwhelm the proteasome, leading to the UBL domain being available for binding to other UIM proteins, which promote aggregate transport to the perinuclear aggresome. PLIC-1, protein linking IAP to the cytoskeleton; Ub, ubiquitin; UBA, ubiquitin-associated domain; UBL, ubiquitin-like; UIM, ubiquitin-interacting motif.