Magnetic sensitivity of cryptochrome 4 from a migratory songbird
Jingjing Xu, Lauren E. Jarocha, Tilo Zollitsch, Marcin Konowalczyk, Kevin B. Henbest,Sabine Richert, Matthew J. Golesworthy, Jessica Schmidt, Victoire Déjean, Daniel J. C. Sowood,Marco Bassetto, Jiate Luo, Jessica R. Walton, Jessica Fleming, Yujing Wei, Tommy L. Pitcher, Gabriel Moise, Maike Herrmann, Hang Yin, Haijia Wu, Rabea Bartölke, Stefanie J. Käsehagen, Simon Horst, Glen Dautaj, Patrick D. F. Murton, Angela S. Gehrckens, Yogarany Chelliah, Joseph S. Takahashi, Karl-Wilhelm Koch, Stefan Weber, Ilia A. Solov'yov, Can Xie, Stuart R. Mackenzie, Christiane R. Timmel, Henrik Mouritsen, P. J. Hore
Night-migratory songbirds are remarkably proficient navigators. Flying alone and often over great distancesthey use various directional cues including, crucially, a light-dependent magnetic compass. The mechanism of thiscompass has been suggested to rely on the quantum spin dynamics of photoinduced radical pairs in cryptochrome flavoproteins located in the retinas of the birds4–7. Here we show that the photochemistry of cryptochrome 4 (CRY4) from the night-migratory European robin (Erithacus rubecula) is magnetically sensitive in vitro, and more so than CRY4 from two non-migratory bird species, chicken (Gallus gallus) and pigeon (Columba livia). Site-specific mutations of ErCRY4 reveal the roles of four successive flavin-tryptophan radical pairs in generating magnetic field effects and in stabilizing potential signalling states in a way that could enable sensing and signalling functions to be independently optimized in night-migratory birds.