Deubiquitinase involved in DNA damage response checkpoint and MYC proto-oncogene stability. Involved in DNA damage induced apoptosis by specifically deubiquitinating proteins of the DNA damage pathway such as CLSPN. Also involved in G2 DNA damage checkpoint, by deubiquitinating CLSPN, and preventing its degradation by the anaphase promoting complex/cyclosome (APC/C). In contrast, it does not deubiquitinate PLK1. Specifically deubiquitinates MYC in the nucleoplasm, leading to prevent MYC degradation by the proteasome: acts by specifically interacting with isoform 1 of FBXW7 (FBW7alpha) in the nucleoplasm and counteracting ubiquitination of MYC by the SCF(FBW7) complex. In contrast, it does not interact with isoform 4 of FBXW7 (FBW7gamma) in the nucleolus, allowing MYC degradation and explaining the selective MYC degradation in the nucleolus.
Belongs to the peptidase C19 family. USP28 subfamily. Contains 1 UIM (ubiquitin-interacting motif) repeat.
Degradaded upon nickel ion level or hypoxia exposure. Phosphorylated upon DNA damage at Ser-67 and Ser-714, by ATM or ATR.
Western blot - Anti-USP28 antibody [EPR4250(2)] (ab110744)
Predicted band size : 122 kDa
Lane 1: Wild-type HAP1 cell lysate (20 µg) Lane 2: USP28 knockout HAP1 cell lysate (20 µg) Lane 3: HeLa cell lysate (20 µg) Lanes 1 - 3: Merged signal (red and green). Green - ab110744 observed at 128 kDa. Red - loading control, ab8245, observed at 37 kDa.
ab110744 was shown to specifically react with USP28 when USP28 knockout samples were used, along with additional cross-reactive bands. Wild-type and USP28 knockout samples were subjected to SDS-PAGE. Ab110744 and ab8245 (loading control to GAPDH) were diluted at 1/500 and 1/10,000 dilution respectively and incubated overnight at 4C. Blots were developed with Goat anti-Rabbit IgG H&L (IRDye® 800CW) preadsorbed ab216773 and Goat anti-Mouse IgG H&L (IRDye® 680RD) preadsorbed ab216776 secondary antibodies at 1/10,000 dilution for 1 hour at room temperature before imaging.
Western blot - USP28 antibody [EPR4250(2)] (ab110744)
All lanes : Anti-USP28 antibody [EPR4250(2)] (ab110744) at 1/1000 dilution
Lane 1 : 293T cell lysate Lane 2 : SW480 cell lysate Lane 3 : HeLa cell lysate Lane 4 : A431 cell lysate