Low-intensity electromagnetic fields induce human cryptochrome to modulate intracellular reactive oxygen species.

Exposure to man-made electromagnetic fields (EMFs), which increasingly pollute our environment, have consequences for human health about which there is continuing ignorance and debate. Whereas there is considerable ongoing concern about their harmful effects, magnetic fields are at the same time being applied as therapeutic tools in regenerative medicine, oncology, orthopedics, and neurology. This paradox cannot be resolved until the cellular mechanisms underlying such effects are identified.

Blue-light induced biosynthesis of ROS contributes to the signaling mechanism of Arabidopsis cryptochrome.

Cryptochromes are evolutionarily conserved blue light receptors with many roles throughout plant growth and development. They undergo conformational changes in response to light enabling interaction with multiple downstream signaling partners. Recently, it has been shown that cryptochromes also synthesize reactive oxygen species (ROS) in response to light, suggesting the possibility of an alternate signaling mechanism.

Blue-light induced accumulation of reactive oxygen species is a consequence of the Drosophila cryptochrome photocycle.

Cryptochromes are evolutionarily conserved blue-light absorbing flavoproteins which participate in many important cellular processes including in entrainment of the circadian clock in plants, Drosophila and humans. Drosophila melanogaster cryptochrome (DmCry) absorbs light through a flavin (FAD) cofactor that undergoes photoreduction to the anionic radical (FAD•-) redox state both in vitro and in vivo. However, recent efforts to link this photoconversion to the initiation of a biological response have remained controversial.

Blue-light dependent ROS formation by Arabidopsis cryptochrome-2 may contribute toward its signaling role.

Cryptochromes are blue-light absorbing flavoproteins with many important signaling roles in plants, including in de-etiolation, development, and stress response. They interact with downstream signaling partners such as transcription factors and components of the proteasome, and thereby alter regulation of nuclear gene expression in a light dependent manner. In a prior study, it has also been shown that Arabidopsis cry1 activation by blue light results in direct enzymatic conversion of molecular oxygen (O2) to ROS (reactive oxygen species) in vivo leading to cell death in overexpressing lines.

Blue-light dependent reactive oxygen species formation by Arabidopsis cryptochrome may define a novel evolutionarily conserved signaling mechanism.

Cryptochromes are widespread blue-light absorbing flavoproteins with important signaling roles. In plants they mediate de-etiolation, developmental and stress responses resulting from interaction with downstream signaling partners such as transcription factors and components of the proteasome. Recently, it has been shown that Arabidopsis cry1 activation by blue light also results in direct enzymatic conversion of molecular oxygen (O2 ) to reactive oxygen species (ROS) and hydrogen peroxide (H2 O2 ) in vitro.