SUMO (small ubiquitin-like modifier) proteins are associated with a number of cellular processes. SUMOylation mediated by SUMO1 is involved in nuclear transport mechanism, apoptosis, regulation of cyclin-dependent kinase 6 and protein stability. SUMO1 regulates tumor suppressor p53 protein, a transcription factor that is termed as the “guardian of the genome” plays a key role in the cell cycle events. Unlike ubiquitination which directs proteins for degradation, SUMOylation aims to alter the stability, localization and the function of the target protein.
