Functional evolution of the photolyase/cryptochrome protein family: importance of the C terminus of mammalian CRY1 for circadian core oscillator performance.
Mol Cell Biol
; 26(5): 1743-53, 2006 Mar.
Article
em En
| MEDLINE
| ID: mdl-16478995
ABSTRACT
Cryptochromes (CRYs) are composed of a core domain with structural similarity to photolyase and a distinguishing C-terminal extension. While plant and fly CRYs act as circadian photoreceptors, using the C terminus for light signaling, mammalian CRY1 and CRY2 are integral components of the circadian oscillator. However, the function of their C terminus remains to be resolved. Here, we show that the C-terminal extension of mCRY1 harbors a nuclear localization signal and a putative coiled-coil domain that drive nuclear localization via two independent mechanisms and shift the equilibrium of shuttling mammalian CRY1 (mCRY1)/mammalian PER2 (mPER2) complexes towards the nucleus. Importantly, deletion of the complete C terminus prevents mCRY1 from repressing CLOCK/BMAL1-mediated transcription, whereas a plant photolyase gains this key clock function upon fusion to the last 100 amino acids of the mCRY1 core and its C terminus. Thus, the acquirement of different (species-specific) C termini during evolution not only functionally separated cryptochromes from photolyase but also caused diversity within the cryptochrome family.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ritmo Circadiano
/
Evolução Molecular
/
Flavoproteínas
Limite:
Animals
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article