Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12Gallus gallusHomo sapiensMacaca mulattaMus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevis home help / support contribute downloads mirrors about us Int. J. Biochem. Cell Biol. (2008); 40(1):147-57 WW domains 2 and 3 of Rsp5p play overlapping roles in binding to the LPKY motif of Spt23p and Mga2p- Bhattacharya S, Zoladek T, Haines DS Fels Institute for Cancer Research and Molecular Biology and the Department of Biochemistry, Temple University School of Medicine, Philadelphia, PA 19140, United States- Abstract: Rsp5p of Saccharomyces cerevisiae is a member of the C2-WW-HECT family of ubiquitin ligases and it interacts with targets via its WW domains- Spt23p and Mga2p are Rsp5p substrates and Rsp5p activates the OLE1 inducing functions of these membrane-localized transcription factors by ubiquitination- Although it is known that Rsp5p binds Mga2p and Spt23p via an imperfect WW domain-binding site -LPKY- that is located within the carboxy-terminal domain of the proteins, it remains unclear which WW domains mediate binding- We show that Rsp5p mutants harboring mutations in single WW domains are Spt23p-Mga2p binding and ubiquitination proficient- This is also the case for WW domains 1-2 and WW domains 1-3 mutants- However, disrupting WW domains 2 and 3 abrogates a physical and functional interaction with substrates in vitro and in cells- We also show that abrogation of WW domains 2 and 3 eliminates the activity of an Rsp5p dominant-negative mutant and an rsp5 WW domain 2-3 mutant is unable to rescue the proliferative defects of rsp5Delta cells- Interestingly, while rsp5Delta cells are able to grow on oleic acid containing YPD media, they as well as those transformed with the WW domain 2-3 mutant are unable to proliferate on oleic acid containing synthetic drop-out media- We conclude from these studies that WW domains 2 and 3 of Rsp5p play overlapping roles in binding to the LPKY site on Spt23p and Mga2p- Also, we propose that WW domains 2 and 3 perform yet to be defined essential function-s- outside of the OLE1 pathway when cells are grown in nutrient restrictive media- [PUBMED: 17719829] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.