Claudins in Caenorhabditis elegans:: Their distribution and barrier function in the epithelium
Claudins in Caenorhabditis elegans:: Their distribution and barrier function in the epithelium
复制标题
DOI：
10.1016/s0960-9822(03)00395-6
复制
发表时间：
2003-06-17
期刊：
影响因子：
9.2
通讯作者：
Tsukita, S
中科院分区：
文献类型：
--
作者：
Asano, A;Asano, K;Tsukita, S
具有四个跨膜区的Claudins(类似于23 kDa)是脊椎动物中主要的细胞黏附分子，在紧密连接处工作，细胞间隙是紧密密封的(在[1-3]中综述)。我们在这里研究了无脊椎动物中可能存在的克劳丁样蛋白，这些无脊椎动物没有典型的紧密连接。对线虫基因组数据库进行的BLAST搜索发现了四个与Claudin相关的、与20 kDa完整膜蛋白(Clc-1至-4)相似的蛋白，它们的序列与脊椎动物的Claudin相似。用GFP技术和免疫荧光显微镜详细检测CLC-1的表达和分布。CLC-1主要表达于消化管咽部的上皮细胞，与AJM-1共定位于细胞间连接处。然后，为了研究ClC-1可能参与屏障功能，我们结合示踪实验进行了RNA干扰：在ClC-1缺陷的蠕虫中，消化管咽部的屏障功能似乎受到了严重影响。ClC-2在皮下组织的缝隙细胞中表达，似乎也参与了皮下屏障的形成。这些发现表明，线虫体内存在多种参与上皮屏障功能的claudin同系物。
Claudins (similar to23 kDa) with four transmembrane domains are major cell adhesion molecules working at tight junctions in vertebrates, where the intercellular space is tightly sealed (reviewed in [1-3]). We examined here the possible occurrence of claudin-like proteins in invertebrates, which do not bear typical tight junctions. Close blast searching of the C. elegans genome database identified four claudin-related, similar to20-kDa integral membrane proteins (CLC-1 to -4), which showed sequence similarity to the vertebrate claudins. The expression and distribution of CLC-1 was then examined in detail by GFP technology as well as by immunofluorescence microscopy. CLC-1 was mainly expressed in the epithelial cells in the pharyngeal region of digestive tubes and colocalized with AJM-1 at their intercellular junctions. Then, to examine the possible involvement of CLC-1 in the barrier function, we performed RNA interference in combination with a tracer experiment: in CLC-1-deficient worms, the barrier function of the pharyngeal portion of the digestive tubes appeared to be severely affected. CLC-2 was expressed in seam cells in the hypodermis, and it also appeared to be involved in the hypodermis barrier. These findings indicated that multiple species of the claudin homologs, which are involved in the barrier function of the epithelium, exist in C. elegans.