Sorting of newly synthesized galactosphingolipids to the two surface domains of epithelial cells
Sorting of newly synthesized galactosphingolipids to the two surface domains of epithelial cells
复制标题
将新合成的半乳鞘脂分选到上皮细胞的两个表面域
作者：
Petra van tier Bijl;M. Lopes‐Cardozo;G. Meer
上皮细胞顶面上的高浓度鞘糖脂可能是通过从其合成位点选择性转运至细胞表面而产生的。以前，我们表明，犬肾MDCK和人肠Caco-2细胞转换携带短荧光脂肪酸C6-NBD的神经酰胺葡萄糖神经酰胺（GlcCer）和鞘磷脂（SM），和GlcCer优先运输到顶端表面相比，SM。在这里，我们解决的一点是，不是所有的鞘糖脂类顶端丰富的上皮细胞。我们表明，含有2-羟基脂肪酸C6 OH的神经酰胺优先转换由MDCK和Caco- 2细胞半乳糖神经酰胺（GalCer）及其衍生物galabiosylceramide（Ga 2Cer）和硫苷脂（SGalCer）相比，SM和GlcCer-所有这些细胞的内源性脂质类。通过BSA消耗测定监测向顶侧和基底侧细胞表面的转运。在MDCK细胞中，GalCer以比GlcCer低2 - 6倍的顶侧/基底侧极性到达细胞表面。值得注意的是，在Caco-2细胞中，GalCer和GlcCer显示出相同的顶侧/底侧极性，但具有C6 OH链的脂质的极性比C6-NBD脂质低六倍。因此，鞘脂的分选似乎取决于脂质结构和细胞类型。我们建议，在各种上皮组织中的葡萄糖和半乳糖鞘脂的合成的不同比例的管理脂质分选的transGolgi网络的膜，通过指定的组成的域从哪里囊泡芽的顶端和基底侧细胞表面。
The high concentration of glycosphingolipids on the apical surface of epithelial cells may be generated by selective transport from their site of synthesis to the cell surface. Previously, we showed that canine kidney MDCK and human intestinal Caco-2 cells converted a ceramide carrying the short fluorescent fatty acid C6-NBD to glucosylceramide (GlcCer) and sphingomyelin (SM), and that GlcCer was preferentially transported to the apical surface as compared to SM. Here, we address the point that not all glycosphingolipid classes are apically enriched in epithelia. We show that a ceramide containing the 2-hydroxy fatty acid C6OH was preferentially converted by MDCK and Caco- 2 cells to galactosylceramide (GalCer) and its derivatives galabiosylceramide (Ga2Cer) and sulfatide (SGalCer) as compared to SM and GlcCer--all endogenous lipid classes of these cells. Transport to the apical and basolateral cell surface was monitored by a BSA- depletion assay. In MDCK cells, GalCer reached the cell surface with two- to sixfold lower apical/basolateral polarity than GlcCer. Remarkably, in Caco-2 cells GalCer and GlcCer displayed the same apical/basolateral polarity, but it was sixfold lower for lipids with a C6OH chain than for C6-NBD lipids. Therefore, the sorting of a sphingolipid appears to depend on lipid structure and cell type. We propose that the different ratios of gluco- and galactosphingolipid synthesis in the various epithelial tissues govern lipid sorting in the membrane of the trans Golgi network by dictating the composition of the domains from where vesicles bud to the apical and basolateral cell surface.
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DOI：
10.1016/s0021-9258(19)38937-9
发表时间：
1990-05
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
A. Futerman;B. Stieger;B. Stieger;A. Hubbard;R. Pagano
通讯作者：
A. Futerman;B. Stieger;B. Stieger;A. Hubbard;R. Pagano
MDCK 上皮细胞中中性糖脂、神经节苷脂和硫酸化脂质的极性。
影响因子：
6.5
作者：
Nichols,GE;Shiraishi,T;YoungJr,WW
通讯作者：
YoungJr,WW
二棕榈酰磷脂酰胆碱和鞘糖脂二元混合物在水分散体中的热致行为。
DOI：
10.1016/0005-2736(85)90131-2
发表时间：
1985
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Maggio,B;Ariga,T;Sturtevant,JM;Yu,RK
通讯作者：
Yu,RK
DOI：
10.1152/ajprenal.1991.260.3.f291
发表时间：
1991
期刊：
The American journal of physiology
影响因子：
--
作者：
Shayman,JA;Radin,NS
通讯作者：
Radin,NS
Madin-Darby 犬肾细胞顶端分泌胞浆蛋白。
DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Lindstedt,R;Apodaca,G;Barondes,SH;Mostov,KE;Leffler,H
通讯作者：
Leffler,H