SUMO3 Recombinant Protein

SUMO proteins, such as SUMO3, and ubiquitin (see MIM 191339) posttranslationally modify numerous cellular proteins and affect their metabolism and function. However, unlike ubiquitination, which targets proteins for degradation, sumoylation participates in a number of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability (Su and Li, 2002 [PubMed 12383504]).[supplied by OMIM, Mar 2008]

Function: Ubiquitin-like protein which can be covalently attached to target lysines either as a monomer or as a lysine-linked polymer. Does not seem to be involved in protein degradation and may function as an antagonist of ubiquitin in the degradation process. Plays a role in a number of cellular processes such as nuclear transport, DNA replication and repair, mitosis and signal transduction. Covalent attachment to its substrates requires prior activation by the E1 complex SAE1-SAE2 and linkage to the E2 enzyme UBE2I, and can be promoted by an E3 ligase such as PIAS1-4, RANBP2 or CBX4. Ref.9 Ref.15

Subunit structure: Covalently attached to a number of proteins

By similarity. Interacts with USP25 (via ts SIM domain); the interaction sumoylates USP25 and inhibits its ubiquitin hydrolyzing activity. Interacts with SAE2 and UBE2I. Ref.9 Ref.11 Ref.15

Subcellular location: Cytoplasm Ref.10.

Tissue specificity: Expressed predominantly in liver. Ref.13

Post-translational modification: Polymeric chains can be formed through Lys-11 cross-linking.Cleavage of precursor form by SENP1, SENP2 or SENP5 is necessary for function.

Sequence similarities: Belongs to the ubiquitin family. SUMO subfamily.Contains 1 ubiquitin-like domain.

Caution: Frequently wrongly assigned as SMT3A in many databases and publications. However, according to initial nomenclature, SUMO3 corresponds to SMT3B (Ref.8).