関連する実験動画
Updated: Aug 6, 2025
05:07
Using Looming Visual Stimuli to Evaluate Mouse Vision
Published on: June 13, 2019
11.4K
超高速な構造変化が 視覚の最初の分子現象を導きます
Thomas Gruhl1, Tobias Weinert1, Matthew J Rodrigues1
1Division of Biology and Chemistry, Laboratory for Biomolecular Research, Paul Scherrer Institute, Villigen PSI, Switzerland.
Nature
|March 23, 2023
まとめ
研究者は超高速結晶学を用いて 網膜に蓄積された光エネルギーが 視覚に必要な最初のタンパク質変化を 駆動する仕組みを明らかにしました これは視覚信号伝達とGタンパク質結合受容体の活性化の初期段階を説明する.
科学分野:
- 生物化学
- 構造生物学
- 分子生物物理学
背景:
- 視力は光に敏感なGタンパク質結合受容体 (GPCR) から始まります
- 11-cis網膜によるフォトンの吸収は,全トランス網膜へのイソメリゼーションを誘発し,視覚信号伝導を開始します.
- 光活性化された網膜がロドプシンにおける構造変化を誘発する正確なメカニズムは完全に理解されていません.
研究 の 目的:
- 光活性化された網膜がロドプシンに構造変化を起こさせる分子内メカニズムを解明する.
- タンパク質を活性化するために フォトンの吸収からエネルギーがどのように蓄えられ 放出されるかを理解する
- 光活性化後のロドプシン初期の構造動態を調査する.
主な方法:
- 室温での超高速時間解像度結晶学
- 光活性化後のピコ秒時間スケールでのロドプシン構造変化の分析.
主要な成果:
- 光活性化後1ピコ秒で,同体化された網膜は歪み,結合ポケットの相互作用から離れる.
- 過剰な光子エネルギーは,アニソトロピックなタンパク質の"呼吸"運動によって細胞外空間へと放出されます.
- 初期のタンパク質側鎖の動きは,後のGタンパク質結合受容体の活性化にとって重要な領域で発生する.
結論:
- この研究は,吸収された光子のエネルギーが 歪んだ網膜に蓄えられ,タンパク質の構造変化を起こすために放出される方法を示しています.
- 初期の構造ダイナミクスは,視覚とGPCRの活性化の基本的な分子機構の洞察を提供します.
- 発見は脊椎動物の視覚の初期段階と クラスAのGPCR活性化経路を明らかにします
関連する概念動画
01:22Photoreceptors and Visual Pathways
6.2K
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,...
6.2K
01:24Vision
54.0K
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
54.0K
01:20Anatomy of the Eyeball
7.3K
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...
7.3K
01:26Visual System
632
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
632
01:32The Retina
69.4K
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.
69.4K