Excess Met1-linked ubiquitination leads to solid aggregate formation.

Excess Met1-linked ubiquitination caused by HOIL-1 inactivation leads to solid aggregate formation and impaired autophagy in cells.

• Why it matters: Understanding how ubiquitin chain regulation affects cellular proteostasis is crucial, as disruptions are linked to neurodegenerative diseases and protein aggregation disorders.
• What they did: The study used cells with catalytically inactive HOIL-1 and OTULIN depletion to increase Met1-linked ubiquitin chains, observing effects on protein aggregation and autophagic flux.
• The result: Findings reveal that excess Met1-linked ubiquitination impairs aggregate clearance by disrupting autophagy, highlighting HOIL-1’s role in maintaining cellular proteostasis and preventing solid aggregate formation.