USP5 protein selectively cleaves branched multiubiquitin polymers, favoring 'Lys-48'-linked polyubiquitin disassembly. It exhibits lower affinity for linear and 'Lys-63'-linked polyubiquitin. USP5 knockdown leads to p53/TP53 accumulation, enhancing p53/TP53 transcriptional activity, as unanchored polyubiquitin competes with ubiquitinated p53/TP53 for proteasomal recognition, unlike MDM2. USP5 Protein, Human (sf9, His) is the recombinant human-derived USP5 protein, expressed by Sf9 insect cells , with C-His labeled tag.
USP5 是一种去泛素化酶，表现出对切割线性和支链多泛素聚合物的明显偏好，对支化结构具有特殊的亲和力。它积极参与未锚定“Lys-48”连接的多聚泛素链的分解。虽然 USP5 以相对较低的亲和力结合线性和“Lys-63”连接的多聚泛素，但其敲低会导致 p53/TP53 的积累和 p53/TP53 转录活性的升高。这种效应归因于在没有 USP5 的情况下，未锚定的多聚泛素能够与泛素化的 p53/TP53 竞争，但不与 MDM2 竞争蛋白酶体的识别。