• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by Colloidal Coomassie? Blue stain

• Activity

  Rabbit Isopeptidase T/USP5 is a Ubiquitin-specific deconjugating enzyme. Reaction conditions will need to be optimized for each specific application. We recommend an initial Rabbit Isopeptidase T/USP5 concentration of 10-100 nM.

• Source

  Rabbit erythrocytes

• Predicted Molecular Mass

  97 kDa

Background: Isopeptidase T/USP5

Isopeptidase T/Ubiquitin Specific Peptidase 5 (USP5) is a widely expressed deubiquitinating enzyme belonging to the peptidase C19 family (1). It is the only known member that requires zinc binding to be active (2). It has a predicted molecular weight of 95.8 kDa (3). Human Isopeptidase T/USP5 is 858 amino acids (aa) in length and shares 98% aa sequence identity with the mouse and rat orthologs (3). Isopeptidase T/USP5 is largely responsible for the disassembly of unanchored poly-Ubiquitin chains. It binds multiple Ubiquitin molecules in a poly-Ubiquitin chain and can cleave Lys29-, Lys48- and Lys63-linked chains (1,4,5). It contains four putative Ubiquitin-binding domains: an N-terminal zinc finger Ubiquitin-binding (ZnF-UBP) domain, a Ubiquitin-specific processing protease (UBP) catalytic domain, and two Ubiquitin-associated domains (UBA1 and UBA2) (5-7). The ZnF-UBP domain (aa 163-291) selectively interacts with an unmodified C-terminus of poly-Ubiquitin chains and induces a conformational change that prevents Isopeptidase T/USP5 from disassembling poly-Ubiquitin until another deubiquitinating enzyme has released the chain from the ubiquitinated protein (5,6,8). The UBP domain binds the second Ubiquitin in poly-Ubiquitin, while the subsequent Ubiquitins bind the UBA2 (aa 722-762) and UBA1 (aa 654-695) domains (5,7). There are short and long forms of human Isopeptidase T/USP5 that differ by an insertion of 23 aa in the long form (2). Suppression of Isopeptidase T/USP5 has been shown to increase the amount and transcriptional activity of p53 due to the accumulation of unanchored poly-Ubiquitin (9). Conversely, an up-regulation of USP5 has been associated with fetal Down syndrome (10).

• References:

1. Wilkinson, K.D. et al. (1995) Biochemistry 34:14535.

2. Gabriel, J.M. et al. (2002) Biochemistry 41:13755.

3. Falquet, L. et al. (1995) FEBS Lett. 376:233.

4. Raasi, S. et al. (2005) Nat. Struct. Mol. Biol. 12:708.

5. Reyes-Turcu, F.E. et al. (2009) Annu. Rev. Biochem. 78:363.

6. Reyes-Turcu, F.E. et al. (2006) Cell 124:1197.

7. Reyes-Turcu, F.E. et al. (2008) J. Biol. Chem. 283:19581.

8. Avvakumov, G.V. et al. (2012) Biochemistry 51:1188.

9. Dayal, S. et al. (2009) J. Biol. Chem. 284:5030.

10. Engidawork, E. et al. (2001) J. Neural Transm. Suppl.(61):117.

• Long Name:

  Ubiquitin Specific Protease 5

• Entrez Gene IDs:

  8078 (Human); 22225 (Mouse); 297593 (Rat)

• Alternate Names:

  Deubiquitinating enzyme 5; EC 3.1.2.15; EC 3.4.19.12; Isopeptidase T; IsoT; ISOTubiquitin carboxyl-terminal hydrolase 5; ubiquitin isopeptidase T; ubiquitin specific peptidase 5 (isopeptidase T); ubiquitin specific protease 5 (isopeptidase T); ubiquitin thioesterase 5; Ubiquitin thiolesterase 5; ubiquitin-specific protease-5 (ubiquitin isopeptidase T); Ubiquitin-specific-processing protease 5; USP5