SUMO (Small Ubiquitin-like Modifier)

SUMO (Small Ubiquitin-like Modifier) is a small protein that attaches to other proteins in cells to regulate their activity, location, stability, and interactions. Think of SUMO as a molecular tag that helps coordinate cellular processes like gene expression, transport, and DNA repair. Unlike ubiquitin, which often marks proteins for destruction, SUMO primarily fine-tunes protein functions without causing degradation. This process, called sumoylation, is essential for normal cell function and response to stress. Overall, SUMO plays a critical role in maintaining cellular balance and ensuring proteins work correctly within the complex environment of a cell.