p62 or SQSTM1 (sequestosome 1) plays a role in the catabolic metabolism of molecules involved in NF-κB (nuclear factor), mTOR (mammalian target of rapamycin), MAPK (mitogen activated protein kinase), and therefore, is involved in cell cycle and apoptosis. It is thought to function as an oncogene, and its accumulation has been associated with poor prognosis. It is accumulated in cell with defective autophagy, and its cytosolic accumulation is linked with poor prognosis in prostate cancer.
It is responsible for the activation of mammalian target of rapamycin complex 1 (mTORC1) by functioning as an adaptor for mTORC1 lysosomal membrane.
During Dengue virus (DENV) infection, the expression of p62 protein is reduced due to proteasomal degradation, and stable expression of p62 results in decreased DENV replication.
p62 is an autophagy marker, and its accumulation is linked with aberration in autophagic degradation or inhibition of autophagy.
Mutations in this gene result in sporadic and familial Paget disease of bone.
p62 is commonly found in inclusion bodies containing polyubiquitinated protein aggregates, that accumulate in several degenerative diseases. Autophagy is involved in cellular clearance of these protein aggregates.
Autophagy plays an essential role in cellular differentiation, cell death, and aging. Defective autophagy may contribute to certain human diseases such as cancer, neurodegenerative diseases, muscular disorders, and pathogen infections.