Letter | Published:

Addition of human melanopsin renders mammalian cells photoresponsive

Nature volume 433, pages 741745 (17 February 2005) | Download Citation

Subjects

Abstract

A small number of mammalian retinal ganglion cells act as photoreceptors for regulating certain non-image forming photoresponses1,2,3,4,5,6,7,8,9,10. These intrinsically photosensitive retinal ganglion cells express the putative photopigment melanopsin11,12,13. Ablation of the melanopsin gene renders these cells insensitive to light14; however, the precise role of melanopsin in supporting cellular photosensitivity is unconfirmed. Here we show that heterologous expression of human melanopsin in a mouse paraneuronal cell line (Neuro-2a) is sufficient to render these cells photoreceptive. Under such conditions, melanopsin acts as a sensory photopigment, coupled to a native ion channel via a G-protein signalling cascade, to drive physiological light detection. The melanopsin photoresponse relies on the presence of cis-isoforms of retinaldehyde and is selectively sensitive to short-wavelength light. We also present evidence to show that melanopsin functions as a bistable pigment in this system, having an intrinsic photoisomerase regeneration function that is chromatically shifted to longer wavelengths.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    , & Phototransduction by retinal ganglion cells that set the circadian clock. Science 295, 1070–1073 (2002)

  2. 2.

    et al. Melanopsin and rod–cone photoreceptive systems account for all major accessory visual functions in mice. Nature 424, 75–81 (2003)

  3. 3.

    et al. Melanopsin is required for non-image-forming photic responses in blind mice. Science 301, 525–527 (2003)

  4. 4.

    , , & Calcium imaging reveals a network of intrinsically light-sensitive inner-retinal neurons. Curr. Biol. 13, 1290–1298 (2003)

  5. 5.

    , , & Intrinsic light responses of retinal ganglion cells projecting to the circadian system. Eur. J. Neurosci. 17, 1727–1735 (2003)

  6. 6.

    , & Characterization of an ocular photopigment capable of driving pupillary constriction in mice. Nature Neurosci. 4, 621–626 (2001)

  7. 7.

    et al. Identifying the photoreceptive inputs to the mammalian circadian system using transgenic and retinally degenerate mice. Behav. Brain Res. 125, 97–102 (2001)

  8. 8.

    et al. Suppression of melatonin secretion in some blind patients by exposure to bright light. N. Engl. J. Med. 332, 6–11 (1995)

  9. 9.

    , & Persistence of masking responses to light in mice lacking rods and cones. J. Biol. Rhythms 16, 585–587 (2001)

  10. 10.

    et al. Relationship between melatonin rhythms and visual loss in the blind. J. Clin. Endocrinol. Metab. 82, 3763–3770 (1997)

  11. 11.

    , , , & Melanopsin-containing retinal ganglion cells: architecture, projections, and intrinsic photosensitivity. Science 295, 1065–1070 (2002)

  12. 12.

    , , , & Melanopsin in cells of origin of the retinohypothalamic tract. Nature Neurosci. 4, 1165 (2001)

  13. 13.

    , , , & The photopigment melanopsin is exclusively present in pituitary adenylate cyclase-activating polypeptide-containing retinal ganglion cells of the retinohypothalamic tract. J. Neurosci. 22, RC191 (2002)

  14. 14.

    et al. Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice. Science 299, 245–247 (2003)

  15. 15.

    , , , & Melanopsin: An opsin in melanophores, brain, and eye. Proc. Natl Acad. Sci. USA 95, 340–345 (1998)

  16. 16.

    & The rhodopsin system of the squid. J. Gen. Physiol. 41, 501–528 (1958)

  17. 17.

    , , , & Photosensitivity of 10-substituted visual pigment analogues: detection of a specific secondary opsin-retinal interaction. Biochemistry 25, 7026–7030 (1986)

  18. 18.

    & The endogenous chromophore of retinal G protein-coupled receptor opsin from the pigment epithelium. J. Biol. Chem. 274, 6085–6090 (1999)

  19. 19.

    et al. Bistable UV pigment in the lamprey pineal. Proc. Natl Acad. Sci. USA 101, 6687–6691 (2004)

  20. 20.

    et al. Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. J. Neurosci. 21, 6405–6412 (2001)

  21. 21.

    , & An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. J. Physiol. (Lond.) 535, 261–267 (2001)

  22. 22.

    & The primary visual pathway in humans is regulated according to long-term light exposure through the action of a nonclassical photopigment. Curr. Biol. 12, 191–198 (2002)

  23. 23.

    , , , & Melanopsin forms a functional short-wavelength photopigment. Biochemistry 42, 12734–12738 (2003)

  24. 24.

    et al. A novel human opsin in the inner retina. J. Neurosci. 20, 600–605 (2000)

  25. 25.

    , , , & Zebrafish melanopsin: isolation, tissue localisation and phylogenetic position. Brain Res. Mol. Brain Res. 107, 128–136 (2002)

  26. 26.

    et al. Inhibition of receptor/G protein coupling by suramin analogues. Mol. Pharmacol. 50, 415–423 (1996)

  27. 27.

    G proteins and dual control of adenylate cyclase. Cell 36, 577–579 (1984)

  28. 28.

    & Uncoupling of gamma-aminobutyric acid B receptors from GTP-binding proteins by N-ethylmaleimide: effect of N-ethylmaleimide on purified GTP-binding proteins. Mol. Pharmacol. 29, 244–249 (1986)

  29. 29.

    , , & Selective photostimulation of genetically chARGed neurons. Neuron 33, 15–22 (2002)

  30. 30.

    , & Enhancement of NMDA receptor-mediated currents by light in rat neurones in vitro . J. Physiol. (Lond.) 524, 365–374 (2000)

  31. 31.

    et al. Induction of photosensitivity by heterologous expression of melanopsin. Nature doi:10.1038/nature03345 (this issue)

  32. 32.

    et al. Illumination of the melanopsin signaling pathway. Science 307, 600–604 (2005)

Download references

Acknowledgements

This work was supported by a Wellcome Trust Showcase Award (M.W.H. and R.J.L.) and in part by the BBSRC (R.J.L.) and NSBRI through NASA NCC 9-58 (R.J.L. and R. Foster). We are grateful to R.K. Crouch for the gift of 11-cis retinaldehyde, to R. Douglas for scientific discussions and comments on the manuscript, and to K. Wells for help and advice with cell culture.

Author information

Affiliations

  1. Department of Visual Neuroscience, Division of Neuroscience and Psychological Medicine, Imperial College London, Charing Cross Hospital Campus, Fulham Palace Road, London W6 8RF, UK

    • Z. Melyan
    • , E. E. Tarttelin
    •  & M. W. Hankins
  2. Faculty of Life Sciences, Michael Smith Building, University of Manchester, Manchester M13 9PT, UK

    • E. E. Tarttelin
    • , J. Bellingham
    •  & R. J. Lucas

Authors

  1. Search for Z. Melyan in:

  2. Search for E. E. Tarttelin in:

  3. Search for J. Bellingham in:

  4. Search for R. J. Lucas in:

  5. Search for M. W. Hankins in:

Competing interests

The authors declare that they have no competing financial interests.

Corresponding authors

Correspondence to R. J. Lucas or M. W. Hankins.

Supplementary information

PDF files

  1. 1.

    Supplementary Figure 1

    Opsin gene expression in Neuro-2a cells by RT-PCR.

  2. 2.

    Supplementary Figure 2

    Detection of melanopsin and EGFP proteins in Neuro-2a cells by western blot.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature03344

Further reading

Comments

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.