Department of Anatomical Sciences and Neurobiology, Health Sciences Campus, 500 S, Preston Street, University of Louisville, Louisville, KY, USA.
BMC Mol Biol. 2009 Dec 14;10:109. doi: 10.1186/1471-2199-10-109.
Cytoplasmic polyadenylation element binding proteins (CPEBs) regulate translation by binding to regulatory motifs of defined mRNA targets. This translational mechanism has been shown to play a critical role in oocyte maturation, early development, and memory formation in the hippocampus. Little is known about the presence or functions of CPEBs in the retina. The purpose of the current study is to investigate the alternative splicing isoforms of a particular CPEB, CPEB3, based on current databases, and to characterize the expression of CPEB3 in the retina.
In this study, we have characterized CPEB3, whose putative role is to regulate the translation of GluR2 mRNA. We identify the presence of multiple alternative splicing isoforms of CPEB3 transcripts and proteins in the current databases. We report the presence of eight alternative splicing patterns of CPEB3, including a novel one, in the mouse retina. All but one of the patterns appear to be ubiquitous in 13 types of tissue examined. The relative abundance of the patterns in the retina is demonstrated. Experimentally, we show that CPEB3 expression is increased in a time-dependent manner during the course of postnatal development, and CPEB3 is localized mostly in the inner retina, including retinal ganglion cells.
The level of CPEB3 was up-regulated in the retina during development. The presence of multiple CPEB3 isoforms indicates remarkable complexity in the regulation and function of CPEB3.
细胞质多聚腺苷酸化元件结合蛋白（CPEBs）通过与特定 mRNA 靶标的调节基序结合来调节翻译。这种翻译机制已被证明在卵母细胞成熟、早期发育和海马体记忆形成中起着关键作用。关于 CPEB 在视网膜中的存在或功能知之甚少。本研究的目的是根据当前的数据库研究特定 CPEB（CPEB3）的剪接异构体，并表征 CPEB3 在视网膜中的表达。
在这项研究中，我们对 CPEB3 进行了特征描述，其潜在作用是调节 GluR2 mRNA 的翻译。我们确定了当前数据库中 CPEB3 转录本和蛋白质的多个剪接异构体的存在。我们报告了在小鼠视网膜中存在 CPEB3 的八种剪接模式，包括一种新的模式。在所检查的 13 种组织类型中，除一种外，所有模式似乎都是普遍存在的。还证明了这些模式在视网膜中的相对丰度。实验表明，CPEB3 的表达在出生后发育过程中呈时间依赖性增加，并且 CPEB3 主要定位于内视网膜，包括视网膜神经节细胞。
在发育过程中，视网膜中的 CPEB3 水平上调。CPEB3 多种异构体的存在表明 CPEB3 的调节和功能具有显著的复杂性。
