• Purity

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

• Activity

  SUMO1 chains do not readily form     in vitro. However, the role of SUMO1 in poly-SUMO chain formation is an area of intense research. Utilizing Recombinant Human SUMO1 Mutant K7R will ensure that K7-linked chains will not be formed. Reaction conditions will need to be optimized for each specific application. We recommend an initial Recombinant Human SUMO1 Mutant K7R concentration of 10-50 μM.

• Source

  E. coli-derived

• Accession #

Background: SUMO1

Human Small Ubiquitin-like Modifier 1 (SUMO1), also known as Sentrin, UBL1, and SMT3C, is synthesized as a 101 amino acid (aa) propeptide with a predicted molecular weight of 11.5 kDa. Human SUMO1 is the most unique of the four identified SUMO proteins and shares only 44%, 47%, and 41% aa sequence identity with SUMO2, SUMO3, and SUMO4, respectively. In contrast, human SUMO1 shares 100% aa sequence identity with the mouse ortholog. SUMOs are a family of small, related proteins that can be enzymatically attached to a target protein by a post-translational modification process termed SUMOylation (1-3). All SUMO proteins share a conserved Ubiquitin domain and a C-terminal diglycine cleavage/attachment site. Following cleavage of a four aa C-terminal prosegment, the C-terminal glycine residue of SUMO1 is enzymatically attached to a lysine residue on a target protein. In humans, SUMO1 is conjugated to a variety of molecules in the presence of the SAE1/UBA2 SUMO-activating (E1) enzyme and the UBE2I/Ubc9 SUMO-conjugating (E2) enzyme (4,5). In yeast, the SUMO-activating (E1) enzyme is Aos1/Uba2p (6). SUMOylation can occur without the requirement of a specific SUMO ligase (E3), where SUMO1 is transferred directly from UBE2I/Ubc9 to specific substrates. In Alzheimer's disease models SUMO1 has been shown to influence the generation of Amyloid-beta peptide by promoting the accumulation of BACE-1 (7). Covalent modification of Phosphatase and Tensin Homolog Deleted on Chromosome (PTEN) by SUMO1 is thought to regulate tumorigenesis by retaining PTEN at the plasma membrane, an effect that suppresses PI 3-Kinase/Akt-dependent tumor growth (8).

Human SUMO-1 does not contain the exact psi ΚXE consensus sequence found in SUMO-2 andSUMO-3. Within this motif psi represents a large hydrophobic amino acid (I, L, or V), K is the lysine that becomes modified, X is any residue and E is glutamic acid. Many known SUMO-1conjugation sites occur within this consensus sequence, but SUMOylation also occurs on lysine residues located within non-consensus regions. SUMO-1 has been shown to form chains in vitro and in vivo but often the linkage is uncharacterized, and the function of SUMO chains has not yet been fully elucidated. SUMO-1 multimerization in vitro has been shown to occur predominantly via lysines K7, K16 and K17. Mutation of lysine 7 to arginine is useful to investigate mono-SUMOylation requirements or to reduce poly-SUMO chain formation.

• References:

1. Desterro, J.M. et al. (1997) FEBS. Lett. 417:297.

2. Bettermann, K. et al. (2012) Cancer Lett. 316:113.

3. Praefcke, G.J. et al. (2012) Trends Biochem. Sci. 37:23.

4. Okuma, T. et al. (1999) Biochem. Biophys. Res.  Commun. 254:693.

5. Tatham, M.H. et al. (2001) J. Biol. Chem. 276:35368.

6. Johnson, E.S. et al. (1997) EMBO J. 16:5509.

7. Yun, S.M. et al. (2012) Neurobiol Aging. [Epub ahead of print].

8. Huang, J. et al. (2012) Nat. Commun. 3:911.

• Long Name:

  Small Ubiquitin-like Modifier 1

• Entrez Gene IDs:

  7341 (Human); 22218 (Mouse); 301442 (Rat)

• Alternate Names:

  DAP1; GAP modifying protein 1; GAP-modifying protein 1; GMP1SMT3CSMT3H3OFC10UBL1PIC1; PIC1; SENP2; Sentrin; small ubiquitin-related modifier 1; SMT3 homolog 3; SMT3 suppressor of mif two 3 homolog 1 (S. cerevisiae); SMT3 suppressor of mif two 3 homolog 1 (yeast); SMT3; SMT3C; SMT3H3; SUMO1; SUMO-1; Ubiquitin-homology domain protein PIC1; ubiquitin-like 1 (sentrin); Ubiquitin-like protein SMT3C; Ubiquitin-like protein UBL1; UBL1