# p62 / SQSTM1

p62 (made by the SQSTM1 gene) is a multitasking 'adaptor' protein, best known as a selective receptor for autophagy, your cells' recycling system. It grabs cargo that has been tagged for disposal (ubiquitinated) using one part (its UBA domain), and hauls it to the autophagosome by latching onto LC3/GABARAP proteins with another part (its LIR region). But p62 does more than sort trash. It also relays stress signals. It switches on the Nrf2 antioxidant response (by trapping Nrf2's brake, Keap1), and it boosts the growth hub mTORC1 (by recruiting TRAF6 and by amino-acid-dependent scaffolding). Because working autophagy normally chews p62 up, a build-up of p62 in the cell is a handy sign that autophagy has stalled. That build-up shows up in aged tissues, alcoholic liver disease, and many cancers, and it is a recognizable feature of ubiquitin-positive clumps under the microscope.

## Sources

- Bjørkøy G, Lamark T, Brech A, et al.. (2005). p62/SQSTM1 forms protein aggregates degraded by autophagy and has a protective effect on huntingtin-induced cell death. Journal of Cell Biology. https://doi.org/10.1083/jcb.200507002
- Kumar AV, Mills J, Lapierre LR. (2022). Selective autophagy receptor p62/SQSTM1, a pivotal player in stress and aging. Frontiers in Cell and Developmental Biology. https://doi.org/10.3389/fcell.2022.793328

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_Canonical: https://longevity-switzerland.com/en/glossary/p62-sqstm1 · Part of Longevity Cities · Updated 2026-06-22_