1Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
7Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, California 93858-2330 USA
8California Institute for Quantitative Biomedical Research, University of California, San Francisco, California 93858-2330 USA
9Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California 93858-2330 USA
10Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
