Watching G proteins at work.
It has been known for over a century that rod photoreceptors in the living retina contract and swell in response to light. Although it is still not known whether this structural light-response is of any functional significance, it has recently been possible to correlate the underlying molecular processes with the activation and deactivation of the photoreceptor G protein, transducin. The technique of light-scattering allows the monitoring of minute changes in cell dimensions, and using this non-invasive experimental approach it can be shown that certain properties of the coupling between transducin and rhodopsin are different in a structurally well-preserved system as compared with rod material used for conventional biochemical studies. Thus, not unlike a psychiatrist, who often learns more about a patient's 'interiors' by observing the body language than by direct interrogation, a biochemist, studying the 'body language' of a cell, may extract information about delicate 'cell interior processes' that would be perturbed by more direct experimental approaches.
Max-Planck-Institut für Biophysikalische Chemie, Göttingen.
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R
Uhl
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Wagner
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Ryba
D000818:Animals; D008954:Models, Biological; D010786:Photoreceptor Cells / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D015293:Transducin / Q000502:physiology*; D014795:Visual Pathways / Q000378:metabolism / Q000502:physiology
D015293:Transducin