Distinct Expression and Localization of Diacylglycerol Kinase Isozymes in Rat Retina
Distinct Expression and Localization of Diacylglycerol Kinase Isozymes in Rat Retina
复制标题
DOI：
10.1369/0022155413483574
复制
发表时间：
2013-03
影响因子：
3.2
通讯作者：
Y. Hozumi;H. Matsui;F. Sakane;Masahiko Watanabe;K. Goto
中科院分区：
文献类型：
--
作者：
Y. Hozumi;H. Matsui;F. Sakane;Masahiko Watanabe;K. Goto
最近的研究表明，磷脂酰肌醇(PI)信号分子在哺乳动物视网膜中表达，表明它们在其信号转导中具有重要作用。我们先前的研究表明，在大鼠视网膜中，二酰甘油激酶(DGK)同工酶在mRNA水平上以不同的模式表达。然而，人们对视网膜中DGK的性质和形态知之甚少。在这项研究中，我们进行了免疫组织化学分析，在蛋白水平上研究了DGK同工酶在视网膜中的表达和定位。在这里，我们发现DGKβ和DGKι都定位于外丛状层，在该层内光感受器细胞与双极细胞和水平细胞接触。这些同工酶表现出不同的亚细胞定位模式：DGKι以点状方式定位于双极细胞的突触区域，而DGKβ广泛分布于双极细胞和水平细胞的突触下和树突区。然而，Dgkϵ的斑点标记在外限膜上很明显。DGKζ和DGKα主要定位于神经节细胞的细胞核。这些发现显示DGK同工酶在视网膜中有不同的表达和定位，表明每种同工酶的作用不同。
Recent studies have revealed that phosphoinositide (PI) signaling molecules are expressed in mammalian retinas, suggesting their importance in its signal transduction. We previously showed that diacylglycerol kinase (DGK) isozymes are expressed in distinct patterns in rat retina at the mRNA level. However, little is known about the nature and morphological aspects of DGKs in the retina. For this study, we performed immunohistochemical analyses to investigate in the retina the expression and localization of DGK isozymes at the protein level. Here, we show that both DGKβ and DGKι localize in the outer plexiform layer, within which photoreceptor cells make contact with bipolar and horizontal cells. These isozymes exhibit distinct subcellular localization patterns: DGKι localizes to the synaptic area of bipolar cells in a punctate manner, whereas DGKβ distributes diffusely in the subsynaptic and dendritic regions of bipolar and horizontal cells. However, punctate labeling for DGKϵ is evident in the outer limiting membrane. DGKζ and DGKα localize predominantly to the nucleus of ganglion cells. These findings show distinct expression and localization of DGK isozymes in the retina, suggesting a different role of each isozyme.