Activation of a calcium-dependent photoprotein by chemical signalling through gap junctions

K. Dunlap, K. Takeda, Paul Brehm

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

In the hydrozoan coelenterate Obelia geniculata, epithelial cell action potentials trigger light emission from photocyte effector cells1,2 containing obelin, an endogenous calcium-activated photoprotein3-5. As this luminescence is blocked by the removal of extracellular calcium it seemed likely that calcium entry via voltage-gated channels in the photocyte membrane would account for the light emission. However, no inward calcium current was detected in whole cell recordings, from dissociated photocytes and depolarization of isolated photocytes produced no luminescence. In contrast, a voltage-dependent calcium current was recorded from non-luminescent support cells, and activation of this current triggered luminescence in an adjacent photocyte. Surprisingly, light emission was abolished when the gap junctions between the photocyte and support cell were blocked. We conclude that calcium entry into support cells leads to light emission from neighbouring photocytes via chemical signalling through intercellular gap junctions.

Original languageEnglish (US)
Pages (from-to)60-62
Number of pages3
JournalNature
Volume325
Issue number6099
StatePublished - 1987
Externally publishedYes

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Luminescent Proteins
Gap Junctions
Calcium
Luminescence
Light
Intercellular Junctions
Patch-Clamp Techniques
Action Potentials
Epithelial Cells
Membranes

ASJC Scopus subject areas

  • General

Cite this

Activation of a calcium-dependent photoprotein by chemical signalling through gap junctions. / Dunlap, K.; Takeda, K.; Brehm, Paul.

In: Nature, Vol. 325, No. 6099, 1987, p. 60-62.

Research output: Contribution to journalArticle

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