Molecular identification, tissue distribution and subcellular localization of mST3GalV/GM3 synthase.
Molecular identification, tissue distribution and subcellular localization of mST3GalV/GM3 synthase.
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mST3GalV/GM3 合酶的分子鉴定、组织分布和亚细胞定位。
DOI：
10.1093/glycob/10.4.365
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发表时间：
2000
期刊：
影响因子：
4.3
通讯作者：
Tiemeyer,M
中科院分区：
文献类型：
--
作者：
Stern,CA;Braverman,TR;Tiemeyer,M
对果蝇碳水化合物结合蛋白（称为Gliolectin）的小鼠同源物进行分子筛选，获得了编码mST 3GalV/GM 3合酶（CMP-NeuAc：乳糖神经酰胺α 2，3-唾液酸转移酶）的cDNA。原位杂交和免疫组化结果显示，mST 3GalV在神经和非神经组织中的表达存在差异。虽然在中枢神经系统中的所有神经元表达，但将其轴突贡献给有髓鞘传出投射的神经元群体，如小脑浦肯野细胞和脊髓运动神经元，表现出最高的ST 3GalV表达。当用抗mST 3GalV抗血清（指定为CS2）染色时，神经元亚群显示出精细的高尔基体，经常延伸到一个或多个树突状突起中。扩展的空间分布的神经元高尔基体，特别是在脊髓运动神经元，允许共聚焦免疫组织化学共定位的mST 3GalV标记内侧/反式高尔基体，但不是顺式高尔基体或反式高尔基体网络，与以前的观察结果表明，神经节苷脂糖基转移酶是丰富的晚期高尔基室。在非神经组织中，肝脏和睾丸表现出细胞类型特异性CS2染色。在肝脏中，与中央静脉同心的窦状隙环内衬的内皮细胞表达mST 3GalV。枯否细胞也用CS2抗血清染色，但肝细胞表达不可检测。在睾丸的生精小管中，ST 3GalV存在于体细胞（Leydig，Sertoli）和早期生殖细胞（精原细胞和初级精母细胞）中;附睾上皮表现出强烈的ST 3GalV表达。由于GM 3是合成a-和b-系列神经节苷脂的前体，在各种细胞群中mST 3GalV/GM 3合酶表达的范围表明某些细胞类型比其他细胞类型更依赖于神经节苷脂功能。
A molecular screen for a mouse homologue of aDrosophilacarbohydrate binding protein, called Gliolectin, yielded a cDNA encoding mST3GalV/GM3 synthase (CMP-NeuAc: lactosylceramide α2,3-sialyltransferase). Byin situhybridization and immunohistochemistry, mST3GalV exhibits differential expression in neural and non-neural tissues. Although expressed by all neurons in the central nervous system, neuronal populations that contribute their axons to myelinated efferent projections, such as cerebellar Purkinje cells and spinal motorneurons, demonstrate the highest ST3GalV expression. When stained with anti-mST3GalV antiserum (designated CS2), subpopulations of neurons display an elaborate Golgi apparatus, frequently extending into one or more dendritic processes. The extended spatial distribution of the neuronal Golgi apparatus, particularly in spinal motorneurons, allowed the confocal immunohistochemical colocalization of mST3GalV with markers for medial/trans-Golgi but not the cis-Golgi or trans-Golgi network, consistent with previous observations suggesting that ganglioside glycosyltransferases are enriched in late Golgi compartments. Among non-neural tissues, liver and testes demonstrate cell-type specific CS2 staining. In liver, endothelial cells lining a ring of sinusoids, concentric with the central vein, express mST3GalV. Kupffer cells are also stained with CS2 antiserum but hepatocyte expression is undetectable. In the seminiferous tubules of the testes, ST3GalV is found in somatic (Leydig, Sertoli) and early germline cells (spermatogonia and primary spermatocytes); the epididymal epithelium exhibits intense ST3GalV expression. Since GM3 is a precursor for the synthesis of a- and b-series gangliosides, the range of mST3GalV/GM3 synthase expression among various cell populations indicates that certain cell types possess greater reliance on ganglioside function than others.