Now Kay and his team have discovered a small molecule -- one that can be easily developed into a drug -- that controls the intricate molecular cogs or timekeeping mechanisms of cryptochrome
in such a manner that it can repress the production of glucose by the liver.
In many migratory animals, the light-sensitive chemical reactions involving the flavoprotein cryptochrome
(CRY) are thought to play an important role in the ability to sense Earth's magnetic field.
Eleven years ago, Ritz and his colleagues identified cryptochrome
, a protein containing a light-sensitive pigment, as a candidate molecule capable of creating such a reaction.
The research team used fruit flies engineered to lack their own Cryptochrome
(Cry1) molecule, a UV/blue-light photoreceptor already known to be involved in the insects' light-dependent magnetic sense.
The molecule, cryptochrome
, is sensitive to blue and ultraviolet light and is found in fly photoreceptor cells.
The monarch's clock, though, includes an unusual pair of cryptochrome
proteins that help regulate this loop.
His postdoctoral collaborator, Ilia Solov'yov, of the Frankfurt Institute for Advanced Studies, did not know that superoxide was toxic, seeing it instead as an ideal reaction partner in a biochemical process involving the protein cryptochrome
in a bird's eye.
offer evidence that fruit flies with mutations in a cryptochrome
gene have altered circadian rhythms.
The plant photolyase structure provides a much better model to use to study how the cryptochrome
proteins in the human clock function than we have ever had before," says Dr.
Any protein that has a DNA sequence 25-50% similar to that of photolysis, but that lacks photolysis' ability to use blue light to repair UV-induced DNA damage, is called a cryptochrome
(Lin & Todo, 2005; Sancar, 2004).
1) The molecular mechanism of the cells of the master SCN clock, and also cellular oscillators in other nuclei in the brain and peripheral tissues and organs, consists of a discrete number of so-called clock genes--period (Per)1, Per2, Per3, Bmal, Clock, and Cryptochrome
(Cry)--and their clock gene products organized as interacting positive and negative transcription and translation feedback loops, with several auxiliary mechanisms reinforcing their robustness and stability.
8]) with fasting glucose (and/or HOMA-B) [adenylate cyclase 5 (ADCY5); MAP-kinase activating death domain (MADD); cryptochrome
2 (photolyase-like) (CRY2); adrenergic, alpha-2A-, receptor (ADRA2A); fatty acid desaturase 1 (FADS1); prospero homeobox 1 (PROX1); solute carrier family 2 (facilitated glucose transporter), member 2 (SLC2A2); GLIS family zinc finger 3 (GLIS3); and C2 calcium-dependent domain containing 4B (C2CD4B)] and 1 was found to be associated with fasting insulin and HOMA-IR concentrations [insulin-like growth factor 1 (somatomedin C) (IGF1)].