Susan L. Sullivan, Ph.D.

Research Fellow
Section on Molecular Sciences
Laboratory of Molecular Biology

Dr. Sullivan received a B.S. degree from Swarthmore College and a Ph.D. degree from Columbia University. Her Ph.D. studies were conducted with Dr. Max Gottesman and focused on transcriptional regulation. After her Ph.D., she did a post-doctoral fellowship with Dr. Linda Buck at Harvard University where she studied information coding in the mammalian olfactory system. In 1996, Dr. Sullivan joined the Laboratory of Molecular Biology at the NIDCD, where she initiated her current studies on taste receptors and taste cell signal transduction pathways.

Research Statement

Our research is focused on the molecular mechanisms underlying the development and function of the mammalian olfactory system. The initial step in olfactory processing occurs within the olfactory epithelium where odorants bind to odorant receptors present on the surface of olfactory sensory neurons. Odorant receptors are G-protein coupled receptors which are encoded by members of a large multigene family consisting of up to 1000 genes. Each odorant receptor gene is expressed in a small subpopulation of olfactory sensory neurons that are widely distributed in the olfactory epithelium. Despite their wide distribution in the olfactory epithelium, neurons that express a given odorant receptor gene project their axons to highly circumscribed regions of the olfactory bulb. Thus, at the level of the olfactory bulb, odorant receptor input is highly organized generating a precise spatial map of olfactory information.

Current research is directed toward the identification of axonal guidance and target recognition molecules that direct the establishment of this spatial map of information within the olfactory bulb. We have identified and are analyzing several molecules that may be involved in this process based on their early developmental expression by olfactory sensory neurons and/or their synaptic partners in the olfactory bulb. A second area of research is the molecular characterization of the large family of odorant receptors. A heterologous cell expression system is being developed in order to study the functional properties of odorant receptors including ligand specificity, G-protein coupling and selectivity, and ligand-dependent modifications.

Employment Opportunities

Postdoctoral positions are available to study the molecular mechanisms underlying the development and function of the mammalian olfactory system using molecular genetic and gene targeting techniques. Candidates should have a strong background in molecular biology and a Ph.D. and/or M.D. with less than five years of postdoctoral experience. Interested candidates should forward a CV and names of three references to:

Selected Publications

• Sainz E, Cavenagh MM, LopezJimenez ND, Gutierrez JC, Battey JF, Northup JK, Sullivan SL. The G-protein coupling properties of the human sweet and amino acid taste receptors. Developmental Neurobiology 67(7):948–59, 2007.
• Sainz E, Cavenagh MM, Gutierrez JC, Battey JF, Northup JK, Sullivan SL. Functional characterization of human bitter taste receptors. The Biochemical Journal 403(3):537–43, 2007.
• Bartel DL, Sullivan SL, Lavoie EG, Finger TE. Nucleoside Triphosphate Diphosphohydrolase-2 (NTPDase2) is the ecto-ATPase of Type I cells in taste buds. The Journal of Comparative Neurology 497(1):1–12, 2006.
• LopezJimenez ND, Cavenagh MM, Sainz E, Cruz-Ithier MA, Battey JF, Sullivan SL. Two members of the TRPP family of ion channels, Pkd1l3 and Pkd2l1, are co-expressed in a subset of taste receptor cells. Journal of Neurochemistry 98(1):68–77, 2006.
• LopezJimenez ND, Sainz E, Cavenagh MM, Cruz-Ithier MA, Blackwood CA, Battey JF, Sullivan SL. Two novel genes, Gpr113, which encodes a family 2 G-protein-coupled receptor, and Trcg1, are selectively expressed in taste receptor cells. Genomics 85(4):472–82, 2005.
• Sullivan SL. Mammalian chemosensory receptors. Neuroreport 13(1):A9–17, 2002.
• Kurima K, Peters LM, Yang Y, Riazuddin S, Ahmed ZM, Naz S, Arnaud D, Drury S, Mo J, Makishima T, Ghosh M, Menon PS, Deshmukh D, Oddoux C, Ostrer H, Khan S, Riazuddin S, Deininger PL, Hampton LL, Sullivan SL, Battey JF Jr, Keats BJ, Wilcox ER, Friedman TB, Griffith AJ. Dominant and recessive deafness caused by mutations of a novel gene, TMC1, required for cochlear hair-cell function. Nature Genetics 30(3):277–84, 2002.
• Sainz E, Korley JN, Battey JF, Sullivan SL. Identification of a novel member of the T1R family of putative taste receptors. Journal of Neurochemistry 77(3):896–903, 2001.
• Liang Y, Wang A, Belyantseva IA, Anderson DW, Probst FJ, Barber TD, Miller W, Touchman JW, Jin L, Sullivan SL, Sellers JR, Camper SA, Lloyd RV, Kachar B, Friedman TB, Fridell RA. Characterization of the human and mouse unconventional myosin XV genes responsible for hereditary deafness DFNB3 and shaker 2. Genomics 61(3):243–58, 1999.
• Li H, Wu DK, Sullivan SL. Characterization and expression of sema4g, a novel member of the semaphorin gene family. Mechanisms of Development 87(1–2):169–173, 1999.
• Sullivan SL, Adamson MC, Ressler KJ, Kozak CA, Buck LB. The chromosomal distribution of mouse odorant receptor genes. Proceedings of the National Academy of Sciences of the USA 93:884–888, 1996.
• Sullivan SL, Dryer L. Information processing in the mammalian olfactory system. Journal of Neurobiology 30:20–36, 1996.
• Sullivan SL, Bohm S, Ressler KJ, Horowitz LF, Buck LB. Target-independent pattern specification in the olfactory epithelium. Neuron 15:779–789, 1995.
• Sullivan SL, Ressler KJ, Buck LB. Spatial patterning and information coding in the olfactory system. Current Opinion in Genetics and Development 5:516–523, 1995.
• Ressler KJ, Sullivan SL, Buck LB. Information coding in the olfactory system: Evidence for a stereotyped and highly organized epitope map in the olfactory bulb. Cell 79:1245–1255, 1994.

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