Small Ubiquitin-related MOdifier (SUMO) is a protein moiety that is ligated to lysine residues in a variety of transcriptional regulators. Sp3, a member of the family of GC-box binding proteins, is one of the best characterised transcription factors to be modified by SUMO. SUMO modification of Sp3 occurs specifically at a single distinct lysine residue (K551) and is catalysed by the SUMO E3 ligase PIAS1. SUMOylation inhibits the transcriptional capacity of Sp3. The mechanism underlying inhibition of Sp3 by SUMO modification is hitherto not understood. In addition, it is completely unknown, how SUMO modification of Sp3 by PIAS1 is regulated. Thus, this project is aimed to unravel the mechanism that leads to inactivation of Sp3 upon SUMO modification and to identify and analyse PIAS1-associated proteins that might regulate PIAS1 activity and confer specificity towards Sp3 in vivo. Since several other transcription factors are also SUMO modified by PIAS proteins, our work will have a general impact on transcript ional regulation by SUMOylation.
DFG Programme
Research Units
Major Instrumentation
Infrared Imaging System
Instrumentation Group
5170 Elektronenoptische Bildwandlergeräte und Bildverstärker (außer Fernsehanlagen 673)
