Localization of ABCA12 from Golgi apparatus to lamellar granules in human upper epidermal keratinocytes
Localization of ABCA12 from Golgi apparatus to lamellar granules in human upper epidermal keratinocytes
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DOI：
10.1111/j.1600-0625.2007.00614.x
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发表时间：
2007-11-01
影响因子：
3.6
通讯作者：
Shimizu, Hiroshi
中科院分区：
文献类型：
--
作者：
Sakai, Kaori;Akiyama, Masashi;Shimizu, Hiroshi
ABCA12是一种atp结合盒转运蛋白，被认为是一种跨膜脂质转运蛋白。我们报道了有害的ABCA12突变引起表皮颗粒层角质形成细胞的片层颗粒（LG）脂质运输紊乱，导致丑角鱼鳞病，一种严重的遗传性皮肤病。研究ABCA12与葡萄糖神经酰胺和高尔基体标记物的详细定位，以获得阐明ABCA12在人体皮肤中的功能的线索。我们使用抗ABCA12、糖基神经酰胺和两种高尔基体标记物（TGN46和GM130）的抗体对正常人皮肤和培养的角质形成细胞进行了双标记免疫荧光染色。用免疫金电镜研究了ABCA12和葡萄糖神经酰胺在正常人皮肤包埋后和冷冻薄切片上的表达。共聚焦激光扫描显微镜显示，ABCA12和糖基神经酰胺共定位于颗粒层角质形成细胞，以及在高Ca2+条件下通过高尔基体培养到细胞周围的角质形成细胞。包埋后免疫金电镜显示ABCA12和糖基神经酰胺标记与最上层颗粒层角质形成细胞的LG相关。低温显微观察更清楚地观察到LG的片层结构，并在最上层颗粒层细胞中更好地证明了ABCA12和葡萄糖神经酰胺的超微结构定位。这些结果表明ABCA12在人颗粒层角质形成细胞高尔基体到LG的脂质转运中起重要作用。
ABCA12 is an ATP-binding cassette transporter and is thought to act as a transmembrane lipid transporter. We reported that deleterious ABCA12 mutations cause a disturbance in lamellar granule (LG) lipid transport in the epidermal granular layer keratinocytes, resulting in harlequin ichthyosis, a severe genodermatosis. Detailed localization of ABCA12 in comparison with glucosylceramide and Golgi apparatus markers were studied in order to obtain clues to clarify the function(s) of ABCA12 in human skin. We performed double-labelling immunofluorescent staining using antibodies against ABCA12, glucosylceramide and two Golgi apparatus markers (TGN46 and GM130) in normal human skin and cultured keratinocytes. Immunogold electron microscopy for ABCA12 and glucosylceramide was studied on postembedding and cryoultrathin sections of normal human skin. Confocal laser scanning microscopy demonstrated that ABCA12 and glucosylceramide co-localized in the granular layer keratinocytes as well as in keratinocytes cultured in high Ca2+ conditions through the Golgi apparatus to the cell periphery. Postembedding immunogold electron microscopy revealed that both ABCA12 and glucosylceramide labellings were associated with the LG of the uppermost granular layer keratinocytes. Using cryoultramicrotomy, lamellar structures in the LG were more clearly observed, and ultrastructural localization of ABCA12 and glucosylceramide was better demonstrated to LG in the uppermost granular layer cells. These results indicate that ABCA12 plays an important role in lipid transport from the Golgi apparatus to LG in human granular layer keratinocytes.