1. Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
2. Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA.
3. Department of Biology, Center for Smell and Taste, University of Florida, Gainesville, FL 32611, USA.
4. Department of Biology, New York University, New York, NY 10003, USA.
5. Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.