TY  - JOUR
AU  - Berndt, A.
AU  - Kottke, T.
AU  - Breitkreuz, H.
AU  - Dvorsky, R.
AU  - Hennig, S.
AU  - Alexander, M.
AU  - Wolf, E.
TI  - A Novel Photoreaction Mechanism for the Circadian Blue Light Photoreceptor Drosophila Cryptochrome
JO  - The journal of biological chemistry
VL  - 282
SN  - 0021-9258
CY  - Bethesda, Md.
PB  - Soc.
M1  - PreJuSER-59166
SP  - 13011 - 13021
PY  - 2007
N1  - Record converted from VDB: 12.11.2012
AB  - Cryptochromes are flavoproteins that are evolutionary related to the DNA photolyases but lack DNA repair activity. Drosophila cryptochrome (dCRY) is a blue light photoreceptor that is involved in the synchronization of the circadian clock with the environmental light-dark cycle. Until now, spectroscopic and structural studies on this and other animal cryptochromes have largely been hampered by difficulties in their recombinant expression. We have therefore established an expression and purification scheme that enables us to purify mg amounts of monomeric dCRY from Sf21 insect cell cultures. Using UV-visible spectroscopy, mass spectrometry, and reversed phase high pressure liquid chromatography, we show that insect cell-purified dCRY contains flavin adenine dinucleotide in its oxidized state (FAD(ox)) and residual amounts of methenyltetrahydrofolate. Upon blue light irradiation, dCRY undergoes a reversible absorption change, which is assigned to the conversion of FAD(ox) to the red anionic FAD(.) radical. Our findings lead us to propose a novel photoreaction mechanism for dCRY, in which FAD(ox) corresponds to the ground state, whereas the FAD(.) radical represents the light-activated state that mediates resetting of the Drosophila circadian clock.
KW  - Animals
KW  - Cell Line
KW  - Circadian Rhythm
KW  - Cryptochromes
KW  - DNA Repair
KW  - Deoxyribodipyrimidine Photo-Lyase: chemistry
KW  - Drosophila: chemistry
KW  - Drosophila: metabolism
KW  - Drosophila Proteins: chemistry
KW  - Drosophila Proteins: metabolism
KW  - Flavin-Adenine Dinucleotide: chemistry
KW  - Flavin-Adenine Dinucleotide: metabolism
KW  - Flavoproteins: chemistry
KW  - Flavoproteins: metabolism
KW  - Oxidation-Reduction
KW  - Photochemistry
KW  - Photoreceptor Cells, Invertebrate: chemistry
KW  - Photoreceptor Cells, Invertebrate: metabolism
KW  - Cryptochromes (NLM Chemicals)
KW  - Drosophila Proteins (NLM Chemicals)
KW  - Flavoproteins (NLM Chemicals)
KW  - Flavin-Adenine Dinucleotide (NLM Chemicals)
KW  - Deoxyribodipyrimidine Photo-Lyase (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:17298948
UR  - <Go to ISI:>//WOS:000245942800071
DO  - DOI:10.1074/jbc.M608872200
UR  - https://juser.fz-juelich.de/record/59166
ER  -