1987-1989 Research Assistant, Department of Biochemistry and Biophysics, University of Hawaii, Honolulu, HI 1989-1990 Teaching Assistant, Dept. of Biochemistry and Molecular Biology, University of Chicago, IL 1989-1992 Research Assistant, Dept. of Molecular Genetics and Cell Biology, University of Chicago, IL 1992-1995 NIH pre-doctoral trainee, Dept. of Biochemistry and Molecular Biology, University of Chicago, IL 1995-1999 Postdoctoral Fellow, Dept. of Molecular Genetics and Cell Biology, Howard Hughes Medical Institute, University of Chicago, IL 1999-2006 Assistant Professor, Dept. of Biological Chemistry, University of California, Irvine, 2006-2011 Associate Professor, Dept. of Biological Chemistry, University of California, Irvine 2011- Professor, Dept. of Biological Chemistry, University of California, Irvine