mRNA export and sumoylation-Lessons from plants

► Many mRNA-maturation related proteins are present in SUMO proteomes of yeast, animals and plants. ► Mutations in nucleoporins and different stress treatments affect both sumoylation and mRNA export in plants. ► Nuclear protein sumoylation acts upstream of mRNA export in plants. ► A model is proposed for a role of transient sumoylation in mRNA maturation and export surveillance.