Structure of the p62 protein. The blocks indicate domains that mediate association with other proteins or are hypothesized to mediate these associations based upon homology with other proteins. The solid lines below the protein indicate stretches of sequence identity (of 20 amino acids or more) among the mouse, rat, and human p62 proteins. The arrows above the protein indicate the Paget disease-associated mutations identified to date. The splice donor and stop mutations result in a truncated protein lacking the UBA domain. PEST denotes hydrophobic regions that target proteins for rapid degradation (P, proline; E, glutaric acid; S, serine; T, threonine).