Bio-X Seminar - Rhodopsins: Transducing Light to Biological Energy and Vision in the Microbial World

Speaker: Professor John Spudich, The University of Texas.

The primary interest in Dr. Spudich's laboratory is the mechanism by which photosensory receptors sense and transmit information concerning the color, intensity, and pattern of light in the environment. His lab studies a widespread class of photoactive receptor proteins (rhodopsins) that consist of seven transmembrane helices connected by interhelical loops. The helices form a pocket for the photosensitive molecule vitamin-A aldehyde (retinal), and the receptor proteins physically couple to protein transducers that relay signals to sensory pathways in the cytoplasm. These photosensitive heptahelical proteins are used for visual processes of various degrees of sophistication, ranging from detection of light-dark boundaries, light gradients, and light direction by single-cell microorganisms to high-resolution color image detection by higher animal eyes.