Stigmoid bodies contain type I receptor proteins SorLA/LR11 and sortilin: New perspectives on their function
Stigmoid bodies contain type I receptor proteins SorLA/LR11 and sortilin: New perspectives on their function
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DOI：
10.1177/002215540305100615
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发表时间：
2003-06-01
影响因子：
3.2
通讯作者：
Bujo, H
中科院分区：
文献类型：
--
作者：
Gutekunst, CA;Torre, ER;Bujo, H
柱头体（SBs）是神经元细胞质中的结构。SBs主要存在于大鼠的下丘脑区域，含有一种名为亨廷顿蛋白相关蛋白1 （HAP1）的蛋白质。在最近发表的一篇文章中，大的细胞质结构被证明对称为SorLA/LR11的I型受体具有免疫反应性。通过光镜分析，这些结构在大小和脑区域和亚细胞定位上与SBs相似。为了确定这些大点是否与含hap1的SBs相对应，我们在大鼠和小鼠脑组织中使用了载脂蛋白受体LR11不同结构域的特异性抗体进行免疫细胞化学。使用HeLa细胞进行转染研究，以证明抗体的特异性。我们发现，在这两个物种中，LR11结构域11（或液泡分选蛋白10结构域VSP10）的抗体与大的细胞质结构发生免疫反应。在大鼠脑组织切片和神经元培养中进行的共定位免疫标记实验表明，这些lr11免疫反应结构与hap1阳性SBs相对应。电镜观察大鼠下丘脑，进一步证实LR11在SBs中存在，并与HAP1共定位。含有lr11的SBs在下丘脑最为丰富，但在许多脑干核、丘脑和海马中也有发现。我们的数据还表明，sortilin是另一种含有VPS10结构域的跨膜蛋白，定位于大的细胞质点，在下丘脑神经元培养的lr11阳性和hap1阳性SBs中发现。
Stigmoid bodies (SBs) are structures in the cytoplasm of neurons. SBs are mostly found in the hypothalamic region of the rat and contain a protein called huntingtin-associated protein 1 (HAP1). In a recent publication, large cytoplasmic structures were shown to be immunoreactive for a type I receptor called SorLA/LR11. By light microscopic analysis, these structures appeared similar to SBs in size and in brain regional and subcellular localization. To determine whether these large puncta correspond to HAP1-containing SBs, we used antibodies specific to various domains of the apolipoprotein receptor LR11 to perform immunocytochemistry in rat and mouse brain tissue. Transfection studies using HeLa cells were conducted to demonstrate the specificity of the antibodies. We found that, in both species, antibodies to the domain 11 (or VSP10 for vacuolar sorting protein 10 domain) of LR11 immunoreact with large cytoplasmic structures. Co-localization immunolabeling experiments in rat brain tissue sections and in neuron cultures showed that these LR11-immunoreactive structures correspond to HAP1-positive SBs. Electron microscopy was performed in rat hypothalamus and further demonstrated the presence of LR11 in SBs and its co-localization with HAP1. LR11-containing SBs were most abundant in the hypothalamus but were also found in many brainstem nuclei, thalamus, and hippocampus. Our data also show that sortilin, another transmembrane protein containing a VPS10 domain, localizes to large cytoplasmic puncta and is found in LR11-positive and Hap1-positive SBs in hypothalamic neuron cultures.