Control of Drosophila retinoid and fatty acid binding glycoprotein expression by retinoids and retinoic acid: northern, western and immunocytochemical analyses.
Control of Drosophila retinoid and fatty acid binding glycoprotein expression by retinoids and retinoic acid: northern, western and immunocytochemical analyses.
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DOI：
10.1006/exer.1997.0383
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发表时间：
1997-11
影响因子：
3.4
通讯作者：
K. Shim;W. Picking;R. K. Kutty;C. F. Thomas;B. Wiggert;W. S. Stark
中科院分区：
文献类型：
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作者：
K. Shim;W. Picking;R. K. Kutty;C. F. Thomas;B. Wiggert;W. S. Stark
在果蝇中，彻底的类维生素A剥夺是可能的，优化研究维生素A代谢物和视黄酸对视觉系统的影响。视黄酸类物质被发现控制果蝇视蛋白基因的转录和翻译。为了遵循这条调查路线，我们研究了类维生素A对果蝇类维生素A和脂肪酸结合糖蛋白的翻译和转录的影响。蛋白质印迹显示，这种蛋白质在类维生素A充足的果蝇中含量高，而在缺乏类维生素A的果蝇中含量低。在能够激活视蛋白基因转录并且含有包括视黄酸的替代转录激活剂的培养基上生长的蝇产生含有显著量的类视黄酸和脂肪酸结合糖蛋白的提取物。免疫细胞化学证实其缺乏在剥夺苍蝇和其存在于苍蝇饲养或更换这些不同的媒体含有类维生素A或一般营养素。免疫细胞化学定位维甲酸和脂肪酸结合糖蛋白的森珀（锥）细胞和小眼内基质（小眼的感光器间基质）。在视蛋白基因突变体和缺乏受体的突变体中Semper细胞的阳性染色表明类视色素和脂肪酸结合糖蛋白不依赖于视蛋白的存在，并且其不在受体细胞中分别合成。北方印迹表明，相对于正常食物生长的果蝇，在饥饿食物生长的果蝇中类维生素A和脂肪酸结合糖蛋白的mRNA大大减少。虽然类视色素和脂肪酸结合糖蛋白的合成不像视蛋白那样需要发色团前体，但通过包括视黄酸的类视色素对类视色素和脂肪酸结合糖蛋白以及视蛋白转录的控制可能非常相同。我们的研究结果表明，类维生素A和脂肪酸结合糖蛋白可能参与类维生素A的运输。此外，Semper细胞在类维生素A代谢和/或递送方面可能类似于脊椎动物视网膜色素上皮。
In Drosophila, thorough retinoid deprivation is possible, optimizing investigation of the effects of vitamin A metabolites and retinoic acid on the visual system. Retinoids had been found to control transcription and translation of Drosophila's opsin gene. To follow this line of inquiry, we examined the effect of retinoids on the translation and transcription of a Drosophila Retinoid and Fatty Acid Binding Glycoprotein. Western blots showed that this protein is high in retinoid replete flies and low in deprived flies. Flies grown on media capable of activating the opsin gene's transcription and which contain alternate transcription activators including retinoic acid yielded extracts containing significant amounts of Retinoid and Fatty Acid Binding Glycoprotein. Immunocytochemistry confirmed its absence in deprived flies and its presence in flies reared or replaced on these diverse media containing retinoids or general nutrients. Immunocytochemistry localized Retinoid and Fatty Acid Binding Glycoprotein to the Semper (cone) cells and the intraommatidial matrix (the interphotoreceptor matrix of the ommatidium). Positive staining of Semper cells in mutants of the opsin gene and a mutant lacking receptors suggests that Retinoid and Fatty Acid Binding Glycoprotein does not depend on presence of opsin and that it is not synthesized in receptor cells respectively. Northern blots demonstrated greatly diminished mRNA for Retinoid and Fatty Acid Binding Glycoprotein in flies grown on deprivation food relative to flies grown on normal food. Although the synthesis of Retinoid and Fatty Acid Binding Glycoprotein does not require chromophore precursors as does that of opsin, the control of Retinoid and Fatty Acid Binding Glycoprotein and opsin transcription by retinoids including retinoic acid might very well be the same. Our results suggest that Retinoid and Fatty Acid Binding Glycoprotein may be involved in retinoid transport. Also, Semper cells may be analogous to vertebrate retinal pigment epithelium in retinoid metabolism and/or delivery.