Abstract
The E3 ubiquitin ligase neuregulin receptor degrading protein 1 (Nrdp1) mediates the ligand-independent degradation of the epidermal growth factor receptor family member ErbB3/HER3. By regulating cellular levels of ErbB3, Nrdp1 influences ErbB3-mediated signaling, which is essential for normal vertebrate development. Nrdp1 belongs to the tripartite or RBCC (RING, B-box, coiled-coil) family of ubiquitin ligases in which the RING domain is responsible for ubiquitin ligation and a variable C-terminal region mediates substrate recognition. We report here the 1.95 Å crystal structure of the C-terminal domain of Nrdp1 and show that this domain is sufficient to mediate ErbB3 binding. Furthermore, we have used site-directed mutagenesis to map regions of the Nrdp1 surface that are important for interacting with ErbB3 and mediating its degradation in transfected cells. The ErbB3-binding site localizes to a region of Nrdp1 that is conserved from invertebrates to vertebrates, in contrast to ErbB3, which is only found in vertebrates. This observation suggests that Nrdp1 uses a common binding site to recognize its targets in different species. Published by Cold Spring Harbor Laboratory Press.
Original language | English (US) |
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Pages (from-to) | 654-661 |
Number of pages | 8 |
Journal | Protein Science |
Volume | 16 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2007 |
Externally published | Yes |
Keywords
- Crystal structure
- E3 ubiquitin ligase
- ErbB3
- Protein degradation
- Receptor tyrosine kinase
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology