Developmental regulation and structural organization of connexins in epidermal gap junctions.
Developmental regulation and structural organization of connexins in epidermal gap junctions.
复制标题
表皮间隙连接中连接蛋白的发育调节和结构组织。
DOI：
10.1006/dbio.1994.1190
复制
发表时间：
1994
影响因子：
2.7
通讯作者：
Gilula,NB
中科院分区：
文献类型：
--
作者：
Risek,B;Klier,FG;Gilula,NB
用免疫组织化学和超微结构方法分析了发育中的大鼠表皮缝隙连接的发育规律。分别用抗α1(Cx4 3)和β2(Cx2 6)连接蛋白的单抗和多克隆抗体进行免疫双标记，激光扫描共聚焦显微镜观察缝隙连接斑块的分子组成。在胎儿发育早期(胚胎期)，缝隙连接是由α1和β2连接蛋白组成的大连接斑块。在超微结构上，在周皮细胞顶端下缘、周皮/基底层交界处和基底层细胞之间的两层表皮中可见缝隙连接。α-1和β-2连接蛋白利用的第一次“切换”发生在表皮层积开始时，此时β-2在周皮和中间层上部表达下调。在胚胎16岁时，在未分化的层状表皮的所有层中，也可以在超微结构中检测到缝隙连接。交界处大小包括周皮有小斑块(0.0 5μ2)，中间层上部有中等大小的斑块(1μm2)，基底层有很大的斑块(2 5μm2)。缝隙连接成分利用的第二次“转换”与表皮分化(>；E18)相一致，此时β-2优先表达于分化的颗粒层和棘层上部。α-1连接蛋白表达于分化较低的棘层和增殖的基底层。在表皮分化(角质化)后(E18-E20)，周皮中不再能检测到缝隙连接。用激光扫描共聚焦显微镜对免疫双染切片的分析显示，在大的连接斑块内存在潜在的混合和分离的抗原区域。这些结果表明，大间隙连接斑块(>；1μm大小)可以包含连接蛋白的分离结构域，这些连接蛋白含有单一的蛋白质(同源寡聚体)。
The developmental regulation of gap junctions was analyzed in the developing rat epidermis by immunohistochemical and ultrastructural methods. The molecular composition of gap junction plaques was examined by laser scanning confocal microscopy following immuno-double labeling with monoclonal and polyclonal antibodies specific for α1(Cx43) and β2(Cx26) connexins, respectively. During early fetal development (embryonic period), gap junctions were identified as large junctional plaques consisting of α1and β2connexins. Ultrastructurally, gap junctions were detected in the two-layered epidermis between the subapical borders of peridermal cells, at the periderm/basal layer interface, and between the basal cells. The first "switch" in the utilization of α1and β2connexins was observed at the onset of epidermal stratification, when β2expression was down-regulated in the periderm and in the upper part of the intermedium. Gap junctions were also detected ultrastructurally in all layers of the stratified, nondifferentiated epidermis at E16. Junctional sizes included small plaques (0.05 μ2in the periderm, medium-size plaques (1 μm2in the upper part of the intermediate layer, and very large plaques (25 μm2) in the basal layer. The second "switch" in the utilization of gap junction components coincided with epidermal differentiation (>E18), when β2was preferentially expressed in the differentiated granular and upper spinous layers. α1connexin was present in the less differentiated spinous layer and in the proliferating basal layer. Gap junctions were no longer detectable in the periderm following differentiation (keratinization) of the epidermis (E18-E20). An analysis of immuno-double-stained sections by laser scanning confocal microscopy revealed domains of potentially mixed and segregated antigens within large junction plaques. These results indicated that large gap junction plaques (>1 μm in size) can contain segregated domains of connexons, which contain a single protein (homooligomer).