p62/SQSTM1 functions as a signaling hub and an autophagy adaptor

p62/SQSTM1 is a stress-inducible cellular protein that is conserved among metazoans but not in plants and fungi. p62/SQSTM1 has multiple domains that mediate its interactions with various binding partners and it serves as a signaling hub for diverse cellular events such as amino acid sensing and the oxidative stress response. In addition, p62/SQSTM1 functions as a selective autophagy receptor for degradation of ubiqutinated substrates. In the present review, we describe the current knowledge about p62 with regard to mammalian target of rapamycin complex 1 activation, the Keap1-Nrf2 pathway and selective autophagy.