Phototransduction cascade and circadian oscillator in chicken pineal gland

Toshiyuki Okano, Yoshitaka Fukada

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The chicken pineal gland has an endogenous circadian oscillator that controls the diurnal oscillation of N-acetyltransferase activity responsible for melatonin rhythm. It has been speculated that the chicken pineal cell contains a photoreceptive molecule that receives the environmental light signal and transmits the signal to the oscillator for resetting the phase. In spite of several lines of evidence suggesting the similarity between retinal and pineal photon-signal transducing proteins, the identity of the photoreceptive molecule had been an open question. In 1994, we isolated a pineal cDNA encoding a novel photoreceptive molecule and named it "pinopsin." The protein expressed in 293EBNA cells bound 11-cis-retinal to form a blue-sensitive pigment with an absorption maximum at about 470 nm. A putative G-protein interaction site of pinopsin shared a relatively high similarity in amino acid sequence to that of rhodopsin, implying that pinopsin functionally couples with transducin or transducin-like G-protein(s) in the pineal cells. We have cloned a cDNA for chicken pineal transducin α-subunit, and the deduced amino acid sequence contained a potential site to be ADP-ribosylated by pertussis toxin (PTX). Therefore, the transducin-mediated pathway could be blocked by PTX, though previous studies showed that treatment of the cultured chicken pineal cells with PTX had no effect on the light-induced phase-shift of the oscillator. Accordingly, it is unlikely that transducin mediates the light-input pathway to the oscillator, which may involve PTX-insensitive G-protein(s) or some unidentified component(s). The G-protein coupled receptor-mediated signaling processes regulating melatonin synthesis are discussed.

Original languageEnglish
Pages (from-to)145-151
Number of pages7
JournalJournal of Pineal Research
Volume22
Issue number3
Publication statusPublished - 1997 Apr
Externally publishedYes

Fingerprint

Transducin
Light Signal Transduction
Pineal Gland
Pertussis Toxin
Chickens
GTP-Binding Proteins
Melatonin
Light
Amino Acid Sequence
Complementary DNA
Retinaldehyde
Biological Clocks
Acetyltransferases
Rhodopsin
G-Protein-Coupled Receptors
Photons
Adenosine Diphosphate
Proteins

Keywords

  • Chicken
  • Circadian clock
  • Iodopsin
  • Photoreceptor
  • Phototransduction cascade
  • Pinopsin
  • Rhodopsin

ASJC Scopus subject areas

  • Endocrinology

Cite this

Phototransduction cascade and circadian oscillator in chicken pineal gland. / Okano, Toshiyuki; Fukada, Yoshitaka.

In: Journal of Pineal Research, Vol. 22, No. 3, 04.1997, p. 145-151.

Research output: Contribution to journalArticle

@article{225f2d61fd94426f953b731f0af1f469,
title = "Phototransduction cascade and circadian oscillator in chicken pineal gland",
abstract = "The chicken pineal gland has an endogenous circadian oscillator that controls the diurnal oscillation of N-acetyltransferase activity responsible for melatonin rhythm. It has been speculated that the chicken pineal cell contains a photoreceptive molecule that receives the environmental light signal and transmits the signal to the oscillator for resetting the phase. In spite of several lines of evidence suggesting the similarity between retinal and pineal photon-signal transducing proteins, the identity of the photoreceptive molecule had been an open question. In 1994, we isolated a pineal cDNA encoding a novel photoreceptive molecule and named it {"}pinopsin.{"} The protein expressed in 293EBNA cells bound 11-cis-retinal to form a blue-sensitive pigment with an absorption maximum at about 470 nm. A putative G-protein interaction site of pinopsin shared a relatively high similarity in amino acid sequence to that of rhodopsin, implying that pinopsin functionally couples with transducin or transducin-like G-protein(s) in the pineal cells. We have cloned a cDNA for chicken pineal transducin α-subunit, and the deduced amino acid sequence contained a potential site to be ADP-ribosylated by pertussis toxin (PTX). Therefore, the transducin-mediated pathway could be blocked by PTX, though previous studies showed that treatment of the cultured chicken pineal cells with PTX had no effect on the light-induced phase-shift of the oscillator. Accordingly, it is unlikely that transducin mediates the light-input pathway to the oscillator, which may involve PTX-insensitive G-protein(s) or some unidentified component(s). The G-protein coupled receptor-mediated signaling processes regulating melatonin synthesis are discussed.",
keywords = "Chicken, Circadian clock, Iodopsin, Photoreceptor, Phototransduction cascade, Pinopsin, Rhodopsin",
author = "Toshiyuki Okano and Yoshitaka Fukada",
year = "1997",
month = "4",
language = "English",
volume = "22",
pages = "145--151",
journal = "Journal of Pineal Research",
issn = "0742-3098",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Phototransduction cascade and circadian oscillator in chicken pineal gland

AU - Okano, Toshiyuki

AU - Fukada, Yoshitaka

PY - 1997/4

Y1 - 1997/4

N2 - The chicken pineal gland has an endogenous circadian oscillator that controls the diurnal oscillation of N-acetyltransferase activity responsible for melatonin rhythm. It has been speculated that the chicken pineal cell contains a photoreceptive molecule that receives the environmental light signal and transmits the signal to the oscillator for resetting the phase. In spite of several lines of evidence suggesting the similarity between retinal and pineal photon-signal transducing proteins, the identity of the photoreceptive molecule had been an open question. In 1994, we isolated a pineal cDNA encoding a novel photoreceptive molecule and named it "pinopsin." The protein expressed in 293EBNA cells bound 11-cis-retinal to form a blue-sensitive pigment with an absorption maximum at about 470 nm. A putative G-protein interaction site of pinopsin shared a relatively high similarity in amino acid sequence to that of rhodopsin, implying that pinopsin functionally couples with transducin or transducin-like G-protein(s) in the pineal cells. We have cloned a cDNA for chicken pineal transducin α-subunit, and the deduced amino acid sequence contained a potential site to be ADP-ribosylated by pertussis toxin (PTX). Therefore, the transducin-mediated pathway could be blocked by PTX, though previous studies showed that treatment of the cultured chicken pineal cells with PTX had no effect on the light-induced phase-shift of the oscillator. Accordingly, it is unlikely that transducin mediates the light-input pathway to the oscillator, which may involve PTX-insensitive G-protein(s) or some unidentified component(s). The G-protein coupled receptor-mediated signaling processes regulating melatonin synthesis are discussed.

AB - The chicken pineal gland has an endogenous circadian oscillator that controls the diurnal oscillation of N-acetyltransferase activity responsible for melatonin rhythm. It has been speculated that the chicken pineal cell contains a photoreceptive molecule that receives the environmental light signal and transmits the signal to the oscillator for resetting the phase. In spite of several lines of evidence suggesting the similarity between retinal and pineal photon-signal transducing proteins, the identity of the photoreceptive molecule had been an open question. In 1994, we isolated a pineal cDNA encoding a novel photoreceptive molecule and named it "pinopsin." The protein expressed in 293EBNA cells bound 11-cis-retinal to form a blue-sensitive pigment with an absorption maximum at about 470 nm. A putative G-protein interaction site of pinopsin shared a relatively high similarity in amino acid sequence to that of rhodopsin, implying that pinopsin functionally couples with transducin or transducin-like G-protein(s) in the pineal cells. We have cloned a cDNA for chicken pineal transducin α-subunit, and the deduced amino acid sequence contained a potential site to be ADP-ribosylated by pertussis toxin (PTX). Therefore, the transducin-mediated pathway could be blocked by PTX, though previous studies showed that treatment of the cultured chicken pineal cells with PTX had no effect on the light-induced phase-shift of the oscillator. Accordingly, it is unlikely that transducin mediates the light-input pathway to the oscillator, which may involve PTX-insensitive G-protein(s) or some unidentified component(s). The G-protein coupled receptor-mediated signaling processes regulating melatonin synthesis are discussed.

KW - Chicken

KW - Circadian clock

KW - Iodopsin

KW - Photoreceptor

KW - Phototransduction cascade

KW - Pinopsin

KW - Rhodopsin

UR - http://www.scopus.com/inward/record.url?scp=0031115486&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031115486&partnerID=8YFLogxK

M3 - Article

C2 - 9213268

AN - SCOPUS:0031115486

VL - 22

SP - 145

EP - 151

JO - Journal of Pineal Research

JF - Journal of Pineal Research

SN - 0742-3098

IS - 3

ER -