Johns Hopkins University
Election Year: 2010
Primary Section: 24, Cellular and Molecular Neuroscience
Secondary Section: 23, Physiology and Pharmacology
Membership Type: Member
King-Wai Yau's long-standing research interest has been in how light triggers vision in the eye. In the mid-1980s, he was instrumental in solving the phototransduction mechanism in retinal rods and cones. One of his current interests is in understanding in ever greater detail this first step in vision in cones, which human vision specifically depends on critically.
Since the early 2000s, he has also been studying some newly discovered retinal photoreceptors, namely, the intrinsically photosensitive retinal ganglion cells (ipRGCs), which mediate primarily non-image vision (versus the canonical, image vision mediated by the rods and cones). He found that these cells have an extremely low pigment (melanopsin) content -- only about 104 molecules per cell in mouse, compared to about 108 rhodopsin molecules in a mouse rod, despite the much larger volume of the light-sensitive part of the ipRGC. Nonetheless, the ipRGC can still detect and signal the absorption of a single photon. He now examines the cellular mechanism underlying phototransduction in these cells.
In addition, Yau is interested in olfactory transduction in the nose. He has found remarkable similarities but also interesting differences between olfactory transduction and rod/cone phototransduction, both being G-protein signaling pathways mediated by cyclic nucleotides (cAMP in olfaction and cGMP in vision). In contrast to the high-amplification signaling found in rod phototransduction, Yau has found a much lower amplification in olfactory-transduction signaling, which he nonetheless thinks is much more typical of G-protein signaling in general. He now studies the quantitative details in olfactory transduction.