Expression and Localization of Connexins in the Outer Retina of the Mouse
Expression and Localization of Connexins in the Outer Retina of the Mouse
复制标题
DOI：
10.1007/s12031-015-0654-y
复制
发表时间：
2016-02-01
影响因子：
3.1
通讯作者：
Janssen-Bienhold, Ulrike
中科院分区：
文献类型：
--
作者：
Bolte, Petra;Herrling, Regina;Janssen-Bienhold, Ulrike
鉴定构成视杆细胞和视锥细胞之间差距连接通道的蛋白质对于理解视网膜网络内光感受器耦合的功能作用至关重要。在脊椎动物中，连接蛋白构成间隙连接通道的结构组分。已知连接蛋白36在视锥细胞中表达，而广泛的研究未能鉴定在视杆细胞中表达的相应连接蛋白。利用免疫电子显微镜，我们证明，连接蛋白36（Cx36）是目前在缝隙连接的锥，但不是杆光感受器在小鼠视网膜。为了确定视杆细胞连接蛋白，我们使用巢式逆转录聚合酶链反应和测试视网膜和感光细胞样本的信使RNA（mRNA）表达的所有已知的连接蛋白基因。除了connexin36，我们检测到的转录connexin32，connexin43，connexin45，connexin50，和connexin57感光细胞样本。免疫组化显示，连接蛋白43，连接蛋白45，连接蛋白50和连接蛋白57蛋白表达在外丛状层。然而，在视杆细胞和视锥细胞之间的缝隙连接处没有检测到这些连接蛋白作为连接蛋白36的对应物。因此，所寻求的杆状蛋白必须是未知的连接蛋白序列、我们的抗体未检测到的连接蛋白36剪接产物或来自另一间隙连接蛋白家族的蛋白质。
The identification of the proteins that make up the gap junction channels between rods and cones is of crucial importance to understand the functional role of photoreceptor coupling within the retinal network. In vertebrates, connexin proteins constitute the structural components of gap junction channels. Connexin36 is known to be expressed in cones whereas extensive investigations have failed to identify the corresponding connexin expressed in rods. Using immunoelectron microscopy, we demonstrate that connexin36 (Cx36) is present in gap junctions of cone but not rod photo-receptors in the mouse retina. To identify the rod connexin, we used nested reverse transcriptase polymerase chain reaction and tested retina and photoreceptor samples for messenger RNA ( mRNA) expression of all known connexin genes. In addition to connexin36, we detected transcripts for connexin32, connexin43, connexin45, connexin50, and connexin57 in photoreceptor samples. Immunohistochemistry showed that connexin43, connexin45, connexin50, and connexin57 proteins are expressed in the outer plexiform layer. However, none of these connexins was detected at gap junctions between rods and cones as a counterpart of connexin36. Therefore, the sought-after rod protein must be either an unknown connexin sequence, a connexin36 splice product not detected by our antibodies, or a protein from a further gap junction protein family.