ピノプシン (Pinopsin) は,鶏の松果の光受容性分子である
T Okano1, T Yoshizawa, Y Fukada
1Department of Pure and Applied Sciences, College of Arts and Sciences, University of Tokyo, Japan.
Nature
|November 3, 1994
まとめ
研究者らは,鶏の松葉細胞に新しい光感知分子,ピノプシンを特定した. この発見は,鳥の生物学的時計とメラトニン生産の分子メカニズムに光を当てています.
科学分野:
- * 分子生物学 * 分子生物学
- *クロノバイオロジー
- *ビジョン・サイエンス・サイエンス
背景:
- * 鳥類のピネアロサイトは,光の信号を介して昼夜リズムとメラトニン産生を調節する.
- * 桃の光伝導経路は,生物学的時計を理解するために不可欠です.
- * 網膜の棒細胞とピネアロサイトは,光伝導において類似点がある.
研究 の 目的:
- * 鳥類の松葉細胞の光受容性分子を特定するために.
- * 鳥類の生物学的時計の分子機構を解明する.
- * 複製された桃の光受容体を特徴付けるため.
主な方法:
- * 光感受性分子をコードする鶏の桃のcDNAのクローニング.
- * 補完的なDNAを培養細胞に変換する.
- * 発現したタンパク質を11-cis-retinal.で復元する.
主要な成果:
- * 新種のオプシン,ピノプシンという名前は,鶏の桃のcDNAからクローン化されました.
- *鶏のピネールオプシンは,脊椎動物の網膜オプシンと43%から48%のアミノ酸同一性を共有しています.
- *11-cis-retinalで再構成されたピノプシンが,青色に敏感な色素 (λmax ≈ 470 nm) を形成した.
- *ピノプシンをコードする遺伝子は,桃腺に特異的に発現しています.
結論:
- *ピノプシンは,鳥類の桃腺の主要な光センサーとして機能します.
- * この発見は,鳥の昼夜時計の重要な分子成分を明らかにしています.
- * この研究は,光伝導におけるピノプシンの役割に関する機能的証拠を提供します.
関連する概念動画
The Retina
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
Photoreceptors and Plant Responses to Light
Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
Channel Rhodopsins
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...


