1. Department of Biochemistry and Cell Biology, Stony Brook University , Stony Brook, NY 11794-5215 , USA
2. Department of Biology, University of Waterloo , Waterloo, Ontario N2L 3G1 , Canada
3. MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee , Dundee DD1 5EH , UK
4. MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital , Edinburgh EH4 2XU , UK