Figure 2

Regulatory motifs in USP1 amino acid sequence. Schematic representation of USP1 protein showing the position of sequence motifs that contribute to the regulation of its levels, localization and activity. These regulatory motifs include a destruction box or “degron” (orange) that mediates APC/C^Cdh1-mediated degradation of USP1, and two NLSs (blue) that mediate import of the USP1/UAF1 complex into the nucleus. The UAF1-binding region of USP1 is still a matter of some controversy. As indicated within the box, two different motifs have been proposed [73, 74]. The position of the diglycine motif (Gly-Gly), which constitutes the site of USP1 autocleavage, and the residue Ser313, which is the site of Cdk-mediated USP1 phosphorylation, are also indicated.