SUMO1, short for Small Ubiquitin-related Modifier 1, is involved in a post-translational modification process called SUMOylation. This process is crucial for maintaining various cellular functions, regulating nearly every aspect of cellular function, such as protein solubility, aggregation, and protein-protein interactions [2]. SUMOylation can influence protein localization, stability, and activity, thereby participating in numerous biological pathways, including those related to stress response, apoptosis, and cell-cycle regulation.

SUMO1 knockout studies have provided significant insights. In myocardial infarction (MI), SUMO1 knockout exacerbated systolic dysfunction and infarct size. Single-nucleus RNA sequencing showed that in cardiomyocytes, SUMO1 deletion increased the Nppa + Nppb + Ankrd1 + cardiomyocyte subcluster proportion after MI. Also, the conversion of fibroblasts to myofibroblasts subclusters was inhibited, while the proliferation of endothelial cell subsets with neovascularization ability was promoted [1]. In embryonic cells, forced overexpression of SUMO1 was not well-tolerated, and surviving cells redistributed SUMO1 to high-molecular-weight conjugates with undetectable free SUMO1 [3].

In summary, SUMO1 plays essential roles in maintaining normal physiological functions in various cell types. Studies using SUMO1 knockout mouse models have revealed its significance in diseases like myocardial infarction, highlighting its potential as a therapeutic target in such disease areas.