PUBLICATION
Comparative photochemistry of animal type 1 and type 4 cryptochromes
- Authors
- Ozturk, N., Selby, C.P., Song, S.H., Ye, R., Tan, C., Kao, Y.T., Zhong, D., and Sancar, A.
- ID
- ZDB-PUB-090814-5
- Date
- 2009
- Source
- Biochemistry 48(36): 8585-8593 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Deoxyribodipyrimidine Photo-Lyase/chemistry
- Drosophila Proteins/chemistry
- Drosophila Proteins/metabolism
- Drosophila Proteins/radiation effects
- Cell Line
- PubMed
- 19663499 Full text @ Biochemistry
Abstract
Cryptochromes (CRYs) are blue-light photoreceptors with known or presumed functions in light-dependent and light-independent gene regulation in plants and animals. Although the photochemistry of plant CRYs has been studied in some detail, the photochemical behavior of animal cryptochromes remains poorly defined in part because it has been difficult to purify animal CRYs with their flavin cofactors. Here we describe the purification of Type 4 CRYs of zebrafish and chicken as recombinant proteins with full flavin complement and compare the spectroscopic properties of Type 4 and Type 1 CRYs. In addition, we analyzed photo-induced proteolytic degradation of both types of CRYs in vivo in heterologous systems. We find that even though both types of CRYs contain stoichiometric flavin, Type 1 CRY is proteolytically degraded by a light-initiated reaction in Drosophila S2, Zebrafish Z3, and human HEK293T cell lines but Zebrafish CRY4 (Type 4) is not. In vivo degradation of Type 1 CRYs does not require continuous illumination and a single light flash of a millisecond duration leads to degradation of about 80% of Drosophila CRY in 60 min. Finally, we demonstrate that in contrast to animal Type 2 CRYs and Arabidopsis CRY1 neither insect Type 1 nor Type 4 CRYs have autokinase activities.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping