title: Chemical magnetoreception: bird cryptochrome 1a is excited by blue light and forms long-lived radical-pairs.
abstract: Cryptochromes (Cry) have been suggested to form the basis of light-dependent magnetic compass orientation in birds. However, to function as magnetic compass sensors, the cryptochromes of migratory birds must possess a number of key biophysical characteristics. Most importantly, absorption of blue light must produce radical pairs with lifetimes longer than about a microsecond. Cryptochrome 1a (gwCry1a) and the photolyase-homology-region of Cry1 (gwCry1-PHR) from the migratory garden warbler were recombinantly expressed and purified from a baculovirus/Sf9 cell expression system. Transient absorption measurements show that these flavoproteins are indeed excited by light in the blue spectral range leading to the formation of radicals with millisecond lifetimes. These biophysical characteristics suggest that gwCry1a is ideally suited as a primary light-mediated, radical-pair-based magnetic compass receptor.
authors.affiliation: VW Nachswuchgruppe Animal Navigation, IBU, University of Oldenburg, Oldenburg, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Liedvogel
authors.forename: Kiminori
authors.initials: K
authors.lastname: Maeda
authors.forename: Kevin
authors.initials: K
authors.lastname: Henbest
authors.forename: Erik
authors.initials: E
authors.lastname: Schleicher
authors.forename: Thomas
authors.initials: T
authors.lastname: Simon
authors.forename: Christiane R
authors.initials: CR
authors.lastname: Timmel
authors.forename: P J
authors.initials: PJ
authors.lastname: Hore
authors.forename: Henrik
authors.initials: H
authors.lastname: Mouritsen
mesh_terms: D025041:Animal Migration; D000818:Animals; D001717:Birds; D002460:Cell Line; D003001:Cloning, Molecular; D056931:Cryptochromes; D005420:Flavoproteins / Q000737:chemistry*; D005609:Free Radicals; D007313:Insecta; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008954:Models, Biological; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D056931:Cryptochromes; D005420:Flavoproteins; D005609:Free Radicals; D011994:Recombinant Proteins