Small Ubiquitin Related Modifier Protein 3 (SUMO3)

SUMO proteins, such as SUMO3, and ubiquitin 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.

The predicted protein of 103 amino acids was found to be a homolog of the S. cerevisiae SMT3 protein, whose gene was previously isolated as a suppressor of mutations in the MIF2 gene. The most prominent difference between SUMO proteins and ubiquitin is the presence of highly variable N-terminal extensions in the SUMO proteins.Expression of SUMO3 was much lower than that of SUMO2, particularly in HeLa and kidney cell lines.