1 Center for Biomolecular Sciences - m/c 870, University of Illinois at Chicago, 900 S. Ashland Avenue, Chicago, IL 60607, USA.
2 Proteomics Center of Excellence, Northwestern University, 633 Clark Street, Chicago, IL 60208, USA.
3 Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
4 Center for Biomolecular Sciences - m/c 870, University of Illinois at Chicago, 900 S. Ashland Avenue, Chicago, IL 60607, USA. Electronic address: nvazquez@uic.edu.
5 Center for Biomolecular Sciences - m/c 870, University of Illinois at Chicago, 900 S. Ashland Avenue, Chicago, IL 60607, USA. Electronic address: shura@uic.edu.