LIMAN LAB

How do we sense the world around us? This is the question that drives research in the lab. The first step in sensory processing is the transduction of the sensory stimulus into an electrical signal sent to the brain. For most sensory stimuli, the receptors have been discovered, yielding insights into signal transduction, behavior and evolution. We have focused on the taste system, where receptors continue to be identified. In pursuit of the receptor for sour taste, we recently discovered a proton-selective ion channel that is expressed in cells that detect sour tastes (Tu et al, Science 2018).  OTOP1 is a member of a family of proteins unrelated to other ion channels, all of which form proton channels. To understand how these channels conduct protons, in collaboration with the Ward lab at TSRI, we recently solved the structure of OTOP1 and  OTOP3 (Saotome et al, NSMB 2019). These studies pave the way for future work aimed at understanding how these channels are activated and how they achieve such high selectivity for protons.  The lab showed that OTOP1 is requried for sour taste signaling in isolated cells and in animals (Teng et al, Curr Biol, 2019) and more recently (Liang et al, Nat Comm, 2023) that it is required for a component of ammonium taste. Thus, OTOP1 is a proton channel that functions as a pH sensor in the taste system, detecting both changes in extracellular pH (sour tastes) and intracellular pH (ammonium).

OTOP1 is also found in the vestibular system and brown adipose tissue while related channels OTOP2 and OTOP3 are found in the digestive tract and nervous sytem. Our studies  lay the groundwork for future work aimed at understanding the contribution of OTOP1 and other members of the protein family to signaling in  a variety of cellular contexts, in health and disease.

EMILY LIMAN, PhD

Professor of Biological Sciences, Sections of Neurobiology and Molecular and Computational Biology

Professor Liman earned her A.B. from Princeton University Magna Cum Laude and earned a Ph.D. from Harvard University in Neuroscience. She is the 2023 recipient of the Cole award from the biophysical society.