[1] Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA
[2] Univ Calif Irvine, Dept Med, Div Infect Dis, Irvine, CA 92697 USA
[3] Scripps Res Inst, Mol & Integrat Neurosci Dept, La Jolla, CA 92037 USA
[4] Scripps Res Inst, Dept Cell Biol, La Jolla, CA 92037 USA