SUMO-1 is a small ubiquitin-like protein that can be covalently conjugated to other proteins. A family of proteases catalyzes deconjugation of SUMO-1-containing species. Members of this family also process newly synthesized SUMO-1 into its conjugatable form. To understand these enzymes better, we have examined the localization and behavior of the human SUMO-1 protease SENP2. Here we have shown ...

Eukaryotic translation initiation factor 4E (eIF4E) is the cap-binding protein that binds the 5' cap structure of cellular messenger RNAs (mRNAs). Despite the obligatory role of eIF4E in cap-dependent mRNA translation, how the translation activity of eIF4E is controlled remains largely undefined. Here, we report that mammalian eIF4E is regulated by SUMO1 (small ubiquitin-related modifier 1) con...

Similar to ubiquitination, sumoylation covalently attaches a small ubiquitin-like modifier (SUMO) protein (92-97 amino acids) to the ε-amino group of a lysine residue. This is quite different from the classically defined post-translational modifications, such as phosphorylation, acetylation, and methylation, which typically add a small chemical group to the targeted residue. Sumoylation has bee...

We have identified the plant biflavonoid hinokiflavone as an inhibitor of splicing in vitro and modulator of alternative splicing in cells. Chemical synthesis confirms hinokiflavone is the active molecule. Hinokiflavone inhibits splicing in vitro by blocking spliceosome assembly, preventing formation of the B complex. Cells treated with hinokiflavone show altered subnuclear organization specifi...

SUMOylation regulates diverse cellular processes including transcription, cell cycle, protein stability, and apoptosis. A recent research has now revealed the role of SUMO1 in cardiac disorders. Studies have evidenced that failing heart induces SUMO2/3 conjugation. Moreover, increased SUMO2/3- dependent modification has been observed to result in congestive heart disease such as cardiac hypertr...