Target identification and developmental function of the E3 ubiquitin ligase Greul1

• Applicant: Professorin Dr. Annette Borchers
• Subject Area: Developmental Biology
• Term: from 2004 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5423401

Signaling pathways that regulate developmental processes have evolved a host of mechanisms to ensure their precise regulation. One critical mechanism is ubiquitination, which has been implicated in the destruction of key signaling molecules in several critical developmental pathways. We have identified a new E3 ubiquitin ligase, Greul1, which has a unique developmental phenotype in Xenopus embryos. While Greul1 can generate ectopic anterior and neural tissue from epidermis, it can also repress the formation of blood and vessels within the mesoderm. This bi-functional effect is unusual, and may be due to differences in Greul1 ubiquitin targets found in the different sets of tissues. Therefore, a key to understanding the function of Greul1 is to identify its specific target substrates. Here I present a new method to screen for targets of E3 ligases and I will use this approach to find substrates for Greul1. Identification of the substrate can lead us to the developmental pathway that is affected by Greul1 and further our understanding of its mechanistic and developmental function.

• DFG Programme: Research Fellowships
• International Connection: USA
• Cooperation Partner: Professorin Dr. Julie C. Baker