A CD36-related Transmembrane Protein Is Coordinated with an Intracellular Lipid-binding Protein in Selective Carotenoid Transport for Cocoon Coloration
A CD36-related Transmembrane Protein Is Coordinated with an Intracellular Lipid-binding Protein in Selective Carotenoid Transport for Cocoon Coloration
复制标题
DOI：
10.1074/jbc.m109.074435
复制
发表时间：
2010-03-05
影响因子：
4.8
通讯作者：
Tsuchida, Kozo
中科院分区：
文献类型：
--
作者：
Sakudoh, Takashi;Iizuka, Tetsuya;Tsuchida, Kozo
特定的膳食类胡萝卜素的运输途径，从中肠腔的丝腺在家蚕，家蚕，是一个模型系统选择性类胡萝卜素运输，因为几个遗传突变体的缺陷，这一途径的部分已被确定，表现出改变茧色素沉着。在具有黄血（Y）和黄茧（C）两种基因的野生型家蚕中，叶黄素选择性地从血淋巴脂蛋白转移到丝腺细胞，在那里它积累成茧。Y基因编码一种细胞内类胡萝卜素结合蛋白（CBP），含有一个脂质结合结构域，称为类固醇生成急性调节蛋白相关脂质转移结构域。定位克隆和转基因拯救实验表明，C基因编码Cameo 2，一个跨膜蛋白基因，属于CD 36家族基因，其中一些，如哺乳动物SR-BI和果蝇ninaD，被报道为脂蛋白受体或涉及类胡萝卜素转运的视觉系统。在C突变体幼虫中，Cameo 2的表达以特定的方式在丝腺中被强烈抑制，导致无色丝腺和白色茧。Cameo 2表达、CBP表达和黄茧品系丝腺中叶黄素色素沉着的发育概况相关。我们假设叶黄素选择性递送至特定组织需要两种组分的组合：1）CBP作为胞质溶胶中的类胡萝卜素转运蛋白，2）Cameo 2作为细胞表面上的跨膜受体。
The transport pathway of specific dietary carotenoids from the midgut lumen to the silk gland in the silkworm, Bombyx mori, is a model system for selective carotenoid transport because several genetic mutants with defects in parts of this pathway have been identified that manifest altered cocoon pigmentation. In the wild-type silkworm, which has both genes, Yellow blood (Y) and Yellow cocoon (C), lutein is transferred selectively from the hemolymph lipoprotein to the silk gland cells where it is accumulated into the cocoon. The Y gene encodes an intracellular carotenoid-binding protein (CBP) containing a lipid-binding domain known as the steroidogenic acute regulatory protein-related lipid transfer domain. Positional cloning and transgenic rescue experiments revealed that the C gene encodes Cameo2, a transmembrane protein gene belonging to the CD36 family genes, some of which, such as the mammalian SR-BI and the fruit fly ninaD, are reported as lipoprotein receptors or implicated in carotenoid transport for visual system. In C mutant larvae, Cameo2 expression was strongly repressed in the silk gland in a specific manner, resulting in colorless silk glands and white cocoons. The developmental profile of Cameo2 expression, CBP expression, and lutein pigmentation in the silk gland of the yellow cocoon strain were correlated. We hypothesize that selective delivery of lutein to specific tissue requires the combination of two components: 1) CBP as a carotenoid transporter in cytosol and 2) Cameo2 as a transmembrane receptor on the surface of the cells.