Emily R. Liman

Department of Biological Sciences,
Section of Neurobiology

Emily R. Liman

Research Topics

  • Ion channel biophysics
  • Sensory biology
  • Pain and taste transduction

Research Overview


We are interested in how organisms detect and respond to sensory stimuli, particularly as it pertains to the detection of chemical stimuli. Animals respond to sensory stimuli using one of several different sensory organs: the olfactory epithelium (smell), taste buds (taste), vomeronasal organ (pheromones) or noiceptors (painful chemicals and pungent tastes). Our lab uses a combination of electrophysiology, molecular biology, genetics and genomics to identify the receptors for sensory stimuli and to understand how they function.

Current work in the Liman lab is focused on mechanisms of taste and pain signaling and the identification of ion channels that contribute to these processes. In one line of investigation, the lab showed that an ion channel responsible for the detection of spicy mustards, TRPA1, is also activated by carbon dioxide (Wang et al, 2010). This may explain some of the pungency we feel when we drink carbonated beverages. In a separate study, the lab examined the mechanism of taste transduction using genetically modified mice in which subsets of taste cells are fluorescently labeled. Using patch clamp electrophysiology and uv-uncaging of protons, the lab showed sour taste cells have an apically located proton channel and a pH sensitive K+ channel (KIR2.1) that are likely to contribute to the sour sensation (Chang et al, 2010; Bushman et al, 2015; Ye et al, 2016). Using single-cell transcriptomics and electrophysiology-based screening, we have now found that molecule that encodes the proton channel in taste cells. It is encoded by the otopetrin-1 gene, which was previously shown to play a role in the vestibular system, but whose function was not known. Otop1 and related proteins, Otop2 and Otop3, form proton channels when expressed in heterologous expression systems and mutation of Otop1 largely eliminate the proton current in taste cells (Tu et al, 2018). These proteins are widely distributed and their functions remain poorly understood.

for recent news coverage of work in the liman lab

Contact Information

Mailing Address University of Southern California
HNB 301
3614 Watt Way
Los Angeles, CA 90089-2520
Office Location HNB 301
Office Phone (213) 821-1454
Lab Location HNB 307
Lab Phone (213) 821-1453
Office Location HNB 301



  • B.A., Princeton University, 1985.
  • Ph.D., Harvard University, 1992.

Selected Publications

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  • Tu Y-H, Cooper AJ, Teng BT, Chang RB, Artiga DJ, Turner HN, Eric M. Mulhall EM, Ye W, Smith AD and Liman ER.  An Evolutionarily Conserved Gene Family Encodes Proton-Selective Ion Channels (2018). Science PubMed Link
  • Ye W, Chang RB, Bushman JD, Tu YH, Mulhall EM, Wilson CE, Cooper AJ, Chick WS, Hill-Eubanks DC, Nelson MT, Kinnamon SC, Liman ER. (2016). The K+ channel KIR2.1 functions in tandem with proton influx to mediate sour taste transduction. PNAS;113(2):E229-38. (featured on the cover)
  • Bushman JD, Ye W, Liman ER. (2015) A proton current associated with sour taste: distribution and functional properties. FASEB J:3014-26. PubMed
  • Liman ER, Zhang YV, Montell C. (2014) Peripheral coding of taste. Neuron. 81(5):984-1000. doi: 10.1016/j.neuron.2014.02.022. PubMed
  • Chang, R. B., Waters, H., and Liman, E. R. (2010). A proton current drives action potentials in genetically identified sour taste cells. PNAS, 468, 603; 2010, Featured on the cover and in "This week in PNAS", Featured in  Nature "Research Highlights" PubMed Link
  • Wang, Y. Y., Chang, R. B., and Liman, E. R. (2010). TRPA1 is a component of the nociceptive response to CO2. J Neurosci 30, 12958-12963. Featured on the cover and in "This week in the journal." Selected for a "ScienceShot" in Science PubMed Link
  • Wang, Y. Y., Chang, R. B., Waters, H. N., McKemy, D. D., and Liman, E. R. (2008). The Nociceptor Ion Channel TRPA1 Is Potentiated and Inactivated by Permeating Calcium Ions. J Biol Chem 283, 32691-32703. PubMed Link
  • Zhang, Z., Zhao, Z., Margolskee, R., and Liman, E. (2007) The transduction channel TRPM5 is gated by intracellular calcium in taste cells. J Neurosci. 27(21):5777-86. PubMed Link
  • E. R. Liman and H. Innan (2003). Relaxed selective pressure on an essential component of pheromone transduction in primate evolution PNAS. 100:3328-3332. PubMed Link
  • D. Liu and Liman, E.R. (2003) Intracellular Ca2+ and the phospholipid PIP2 regulate the taste transduction channel TRPM5. PNAS. 100(25):15160-15165. PubMed
  • Liman, E.R., Corey, D.P., and Dulac, C. (1999) TRP2, a candidate transduction channel for mammalian pheromone sensory signalling. PNAS. 96:5791-5796 PubMed