1. Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
2. Department of Biological Chemistry, College of Medicine, University of California, Irvine, CA 92697, USA
3. Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
4. The Fox Chase Cancer Institute, Philadelphia, PA 19111, USA
5. Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh, EH9 3JR, UK
6. Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA