SUMO2 Recombinant Protein

This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It functions in a manner similar to ubiquitin in that it is bound to target proteins as part of a post-translational modification system. However, unlike ubiquitin which targets proteins for degradation, this protein is involved in a variety of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. It is not active until the last two amino acids of the carboxy-terminus have been cleaved off. Numerous pseudogenes have been reported for this gene. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

Function: Ubiquitin-like protein that can be covalently attached to proteins as a monomer or as a lysine-linked polymer. Covalent attachment via an isopeptide bond 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. This post-translational modification on lysine residues of proteins plays a crucial role in a number of cellular processes such as nuclear transport, DNA replication and repair, mitosis and signal transduction. Polymeric SUMO2 chains are also susceptible to polyubiquitination which functions as a signal for proteasomal degradation of modified proteins. Ref.7 Ref.15 Ref.16

Subunit structure: Homotrimer

Potential. Crystal packing analysis suggests a possible trimeric assembly, of which the biological significance remains to be determined. Interacts with SAE2 and UBE2I. Covalently attached to a number of proteins. Interacts with PELP1. Interacts with USP25; the interaction sumoylates USP25. Interacts with SIMC1, CASP8AP2, RNF111 AND SOBP (via SIM domains). Ref.11 Ref.14 Ref.15 Ref.19 Ref.20

Subcellular location: Nucleus. Nucleus › PML body Ref.7 Ref.10 Ref.18.

Tissue specificity: Broadly expressed. Ref.7

Post-translational modification: Polymeric chains can be formed through Lys-11 cross-linking. Polymeric SUMO2 chains undergo 'Lys-6'-, 'Lys-11'-, 'Lys-48'- and 'Lys-63'-linked polyubiquitination by RNF4.Cleavage of precursor form by SENP1 or SENP2 is necessary for function.

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

Caution: Frequently wrongly assigned as SMT3B in many databases and publications. However, according to initial nomenclature, SUMO2 corresponds to SMT3A (Ref.8).