Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Regulation of Arabidopsis cryptochrome 2 by blue-light-dependent phosphorylation

An Erratum to this article was published on 25 July 2002


Cryptochromes are blue/ultraviolet-A light receptors that mediate various light responses in plants and animals1,2. But the initial photochemical reaction of cryptochrome is still unclear. For example, although most photoreceptors are known to undergo light-dependent protein modification such as phosphorylation3,4, no blue-light dependent phosphorylation has been reported for a cryptochrome. Arabidopsis cryptochrome 2 (cry2) mediates light regulation of seedling development and photoperiodic flowering5,6. The physiological activity and cellular level of cry2 protein are light-dependent5,6,7,8, and protein–protein interactions are important for cry2 function9,10. Here we report that cry2 undergoes a blue-light-dependent phosphorylation, and that cry2 phosphorylation is associated with its function and regulation. Our results suggest that, in the absence of light, cry2 remains unphosphorylated, inactive and stable; absorption of blue light induces the phosphorylation of cry2, triggering photomorphogenic responses and eventually degradation of the photoreceptor.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Blue-light-dependent phosphorylation of Arabidopsis cry2.
Figure 2: Kinetics analyses of light-dependent cry2 phosphorylation.
Figure 3: Accumulation of phosphorylated cry2 and impairment of cry2 turnover in cop1 mutants in response to blue light.
Figure 4: The lack of effect of red light or phytochrome mutations on cry2 phosphorylation.
Figure 5: Constitutive phosphorylation of the CRY2 C-terminal domain moiety (CCT2) of the GUS–CCT2 fusion protein.


  1. Cashmore, A. R., Jarillo, J. A., Wu, Y. J. & Liu, D. Cryptochromes: blue light receptors for plants and animals. Science 284, 760–765 (1999)

    ADS  CAS  Article  Google Scholar 

  2. Sancar, A. Cryptochrome: the second photoactive pigment in the eye and its role in circadian photoreception. Annu. Rev. Biochem. 69, 31–67 (2000)

    CAS  Article  Google Scholar 

  3. Holmes, M. G. (ed. ) Photoreceptor Evolution and Function (Academic, New York, 1991)

  4. Briggs, W. R. & Huala, E. Blue-light photoreceptors in higher plants. Annu. Rev. Cell Dev. Biol. 15, 33–62 (1999)

    CAS  Article  Google Scholar 

  5. Lin, C. et al. Enhancement of blue-light sensitivity of Arabidopsis seedlings by a blue light receptor cryptochrome 2. Proc. Natl Acad. Sci. USA 95, 2686–2690 (1998)

    ADS  CAS  Article  Google Scholar 

  6. Guo, H., Yang, H., Mockler, T. C. & Lin, C. Regulation of flowering time by Arabidopsis photoreceptors. Science 279, 1360–1363 (1998)

    ADS  CAS  Article  Google Scholar 

  7. Ahmad, M., Jarillo, J. A. & Cashmore, A. R. Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability. Plant Cell 10, 197–208 (1998)

    CAS  PubMed  PubMed Central  Google Scholar 

  8. El-Din El-Assal, S., Alonso-Blanco, C., Peeters, A. J., Raz, V. & Koornneef, M. A QTL for flowering time in Arabidopsis reveals a novel allele of CRY2. Nature Genet. 29, 435–440 (2001)

    CAS  Article  Google Scholar 

  9. Mas, P., Devlin, P. F., Panda, S. & Kay, S. A. Functional interaction of phytochrome B and cryptochrome 2. Nature 408, 207–211 (2000)

    ADS  CAS  Article  Google Scholar 

  10. Wang, H., Ma, L. G., Li, J. M., Zhao, H. Y. & Deng, X. W. Direct interaction of Arabidopsis cryptochromes with COP1 in light control development. Science 294, 154–158 (2001)

    ADS  CAS  Article  Google Scholar 

  11. Laemmli, U. K. Cleavage of structural proteins during the assembly of the head of bacteriaphage T4. Nature 227, 680–685 (1970)

    ADS  CAS  Article  Google Scholar 

  12. Guo, H., Duong, H., Ma, N. & Lin, C. The Arabidopsis blue light receptor cryptochrome 2 is a nuclear protein regulated by a blue light-dependent post-transcriptional mechanism. Plant J. 19, 279–287 (1999)

    CAS  Article  Google Scholar 

  13. Fankhauser, C. & Chory, J. Light control of plant development. Annu. Rev. Cell. Dev. Biol. 13, 203–229 (1997)

    CAS  Article  Google Scholar 

  14. Kwok, S. F., Piekos, B., Misera, S. & Deng, X. W. A complement of ten essential and pleiotropic arabidopsis COP/DET/FUS genes is necessary for repression of photomorphogenesis in darkness. Plant Physiol. 110, 731–742 (1996)

    CAS  Article  Google Scholar 

  15. Buche, C., Poppe, C., Schafer, E. & Kretsch, T. eid1: A. new Arabidopsis mutant hypersensitive in phytochrome A-dependent high-irradiance responses. Plant Cell 12, 547–558 (2000)

    CAS  Article  Google Scholar 

  16. Guo, H., Mockler, T. C., Duong, H. & Lin, C. SUB1, an Arabidopsis Ca2+-binding protein involved in cryptochrome and phytochrome coaction. Science 291, 487–490 (2001)

    ADS  CAS  Article  Google Scholar 

  17. Deng, X.-W., Caspar, T. & Quail, P. H. COP1: a regulatory locus involved in light-controlled development and gene expression in Arabidopsis. Genes Dev. 5, 1172–1182 (1989)

    Article  Google Scholar 

  18. McNellis, T. W. et al. Genetic and molecular analysis of an allelic series of cop1 mutants suggests functional roles for the multiple protein domains. Plant Cell 6, 487–500 (1994)

    CAS  Article  Google Scholar 

  19. Chory, J., Peto, C., Feinbaum, R., Pratt, L. & Ausubel, F. Arabidopsis thaliana mutant that develops as a light-grown plant in the absence of light. Cell 58, 991–999 (1989)

    CAS  Article  Google Scholar 

  20. Osterlund, M. T., Hardtke, C. S., Wei, N. & Deng, X. W. Targeted destabilization of HY5 during light-regulated development of Arabidopsis. Nature 405, 462–466 (2000)

    ADS  CAS  Article  Google Scholar 

  21. Yang, H. Q., Tang, R. H. & Cashmore, A. R. The signalling mechanism of Arabidopsis CRY1 involves direct interaction with COP1. Plant Cell 13, 2573–2587 (2001)

    CAS  Article  Google Scholar 

  22. Yeh, K. C. & Lagarias, J. C. Eukaryotic phytochromes: light-regulated serine/threonine protein kinases with histidine kinase ancestry. Proc. Natl Acad. Sci. USA 95, 13976–13981 (1998)

    ADS  CAS  Article  Google Scholar 

  23. Ahmad, M., Jarillo, J. A., Smirnova, O. & Cashmore, A. R. The CRY1 blue light photoreceptor of Arabidopsis interacts with phytochrome A in vitro. Mol. Cell 1, 939–948 (1998)

    CAS  Article  Google Scholar 

  24. Mockler, T. C., Guo, H., Yang, H., Duong, H. & Lin, C. Antagonistic actions of Arabidopsis cryptochromes and phytochrome B in the regulation of floral induction. Development 126, 2073–2082 (1999)

    CAS  PubMed  Google Scholar 

  25. Devlin, P. F. et al. Phytochrome D acts in the shade-avoidance syndrome in Arabidopsis by controlling elongation growth and flowering time. Plant Physiol. 119, 909–915 (1999)

    CAS  Article  Google Scholar 

  26. Devlin, P. F., Patel, S. R. & Whitelam, G. C. Phytochrome E influences intermode elongation and flowering time in Arabidopsis. Plant Cell 10, 1479–1488 (1999)

    Article  Google Scholar 

  27. Parks, B. M. & Quail, P. H. Phytochrome-deficient hy1 and hy2 long hypocotyl mutants of Arabidopsis are deficient in chromophore biosynthesis. Plant Cell 3, 1177–1186 (1991)

    CAS  Article  Google Scholar 

  28. Yang, H.-Q. et al. The C termini of Arabidopsis cryptochromes mediate a constitutive light response. Cell 103, 815–827 (2000)

    CAS  Article  Google Scholar 

  29. Lin, C., Ahmad, M. & Cashmore, A. R. Arabidopsis cryptochrome 1 is a soluble protein mediating blue light-dependent regulation of plant growth and development. Plant J. 10, 893–902 (1996)

    CAS  Article  Google Scholar 

Download references


We thank T. Cashmore, X.-W. Deng, J. Chory and T. Kretsch for providing Arabidopsis mutant lines. This work is supported by research grants from the National Institutes of Health, the National Science Foundation and UCLA-FGP. T.C.M. is supported by a predoctoral UCLA-NSF/IGERT training award.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Chentao Lin.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Shalitin, D., Yang, H., Mockler, T. et al. Regulation of Arabidopsis cryptochrome 2 by blue-light-dependent phosphorylation. Nature 417, 763–767 (2002).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing