Jans D A, Peters R, Fahrenholz F
Max-Planck-Institut für Biophysik, Frankfurt/Main, FRG.
FEBS Lett. 1990 Nov 12;274(1-2):223-6. doi: 10.1016/0014-5793(90)81368-x.
Lateral mobility of the vasopressin renal-type V2-receptor was investigated in LLC-PK1 porcine epithelial cells using the technique of fluorescence microphotolysis (photobleaching) and a rhodamine-labelled vasopressin analogue. At various times after ligand addition, cells were analyzed for both receptor lateral mobility and ligand internalization. The V2-receptor mobile fraction diminished from 0.9 to 0.43 over 60 min at 37 degrees C, whereas the apparent lateral diffusion coefficient remained essentially unchanged (2-3 X 10(-10) cm2/s). Interestingly, the fraction of immobile V2-receptors corresponded exactly with the fraction of internalized receptors, implying a functional relationship. These observations together with comparable results reported for other polypeptide hormone receptors indicate a possible mechanistic role for receptor immobilization in the desensitization of hormonal response.
利用荧光显微光解（光漂白）技术和一种罗丹明标记的血管加压素类似物，在LLC-PK1猪上皮细胞中研究了血管加压素肾型V2受体的横向移动性。在添加配体后的不同时间，对细胞进行受体横向移动性和配体内化分析。在37℃下，V2受体的可移动部分在60分钟内从0.9降至0.43，而表观横向扩散系数基本保持不变（2 - 3×10⁻¹⁰ cm²/s）。有趣的是，不可移动的V2受体部分与内化受体部分恰好对应，这意味着存在功能关系。这些观察结果以及针对其他多肽激素受体报道的类似结果表明，受体固定在激素反应脱敏中可能具有机制作用。
