The biophysical, molecular, and anatomical landscape of pigeon CRY4: A candidate light-based quantal magnetosensor

• Published in: Science advances 2020-08, Vol.6 (33), p.eabb9110-eabb9110
• Main Authors: Hochstoeger, Tobias, Al Said, Tarek, Maestre, Dante, Walter, Florian, Vilceanu, Alexandra, Pedron, Miriam, Cushion, Thomas D, Snider, William, Nimpf, Simon, Nordmann, Gregory Charles, Landler, Lukas, Edelman, Nathaniel, Kruppa, Lennard, Dürnberger, Gerhard, Mechtler, Karl, Schuechner, Stefan, Ogris, Egon, Malkemper, E Pascal, Weber, Stefan, Schleicher, Erik, Keays, David A
• Format: Article
• Language: English
• Subjects: Cellular Neuroscience; Neuroscience; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abb9110

The biophysical and molecular mechanisms that enable animals to detect magnetic fields are unknown. It has been proposed that birds have a light-dependent magnetic compass that relies on the formation of radical pairs within cryptochrome molecules. Using spectroscopic methods, we show that pigeon cryptochrome clCRY4 is photoreduced efficiently and forms long-lived spin-correlated radical pairs via a tetrad of tryptophan residues. We report that clCRY4 is broadly and stably expressed within the retina but enriched at synapses in the outer plexiform layer in a repetitive manner. A proteomic survey for retinal-specific clCRY4 interactors identified molecules that are involved in receptor signaling, including glutamate receptor-interacting protein 2, which colocalizes with clCRY4. Our data support a model whereby clCRY4 acts as an ultraviolet-blue photoreceptor and/or a light-dependent magnetosensor by modulating glutamatergic synapses between horizontal cells and cones.