NaIO3-Induced Mouse Model of Aging-Related Macular Degeneration Displayed Altered Expression Patterns of Sumoylation Enzymes E1, E2 and E3.

Protein sumoylation is a highly dynamic and reversible post-translational modification, involving covalently conjugation of the small ubiquitin-like modifier (SUMO) to the lysine residue of the target protein. Similar to ubiquitination, sumoylation is catalyzed by E1, E2 and several E3 ligases. However, sumoylation usually does not cause protein degradation but alter the target function through diverse mechanisms. Increasing evidences have shown that sumoylation plays pivotal roles in the pathogenesis of human diseases, including neuron degeneration, cancer and heart disease, etc. We and others have shown that sumoylation is critically implicated in mouse eye development. However, the expression of sumoylation machinery has not been characterized in normal and pathogenic retina. Worldwide, age-related macular degeneration (AMD) is the leading cause of irreversible blindness in aged person. In the present study, we investigated the expression of the major sumoylation enzymes in normal mice and sodium iodate-induced AMD mouse model. Dynamic expression of E1, E2 and E3 enzymes were found during the time course of RPE and retina degeneration, which revealed the potential regulatory roles of sumoylation in AMD pathogenesis.