ZFP36L2-mRNA Interaction: Drawing general rules based on transcriptomic analysis. ZFP36L2-mRNA Interaction: Drawing general rules based on transcriptomic analysis

In this study we focus on identifying potential physiological targets of ZFP36L2 (Zinc finger protein like 2 or L2), one of the three primate members of the ZFP36 protein family. Most studies on ARE specificity of this small family were conducted using the prototypical family member, ZFP36 or TTP; however, less is known about the other family member’s specificity. Previous studies of ZFP36L2 target mRNAs identified a high proportion of transcription factors in two different systems, cells from the erythrocyte lineage and oocytes. However, there is minimal overlap between the genes identified in these studies and those identified here using mouse spleens lacking ZFP36L2 (L2-cKO). This observation suggests that ZFP36L2 targeting is occurring in a highly tissue specific manner. Aiming to understand what factors govern this potential tissue specificity, we characterized the differentially expressed genes in our L2-cKO mouse model in the spleen, an organ that expresses L2 at high levels in humans and mice. We performed transcriptome-wide analysis in RNA spleen samples from mice lacking ZFP36L2 (L2-cKO) and normally expressing (WT). Differential gene expression (DEG) of WT vs. L2-cKO spleens revealed 549 up regulated and 603 down regulated genes. Nine genes were validated in qPCR assays. Overall design: Adenine-uridine rich element-RNA-binding proteins (ARE-RBP) generally either stabilize or destabilize the target transcripts they bind. A remaining challenge in the field is understanding the specificity of targeting by ARE-RBPs and how this dictates function. We performed transcriptome-wide analysis in RNA spleen samples from mice lacking ZFP36L2 (L2-cKO) and normally expressing (WT).

本研究聚焦于鉴定ZFP36L2（锌指蛋白样2，Zinc finger protein like 2，简称L2）的潜在生理靶标。ZFP36L2是ZFP36蛋白家族的三个灵长类成员之一。针对该小家族的腺嘌呤尿嘧啶富集元件（Adenine-uridine rich element, ARE）结合特异性的多数研究，均以该家族的原型成员ZFP36（又称TTP）为研究对象，但对于其他家族成员的结合特异性，目前所知甚少。既往针对ZFP36L2靶标mRNA的研究，在红细胞谱系细胞与卵母细胞两类不同实验体系中，均鉴定出了高比例的转录因子。然而，上述研究中鉴定出的基因，与本研究利用缺失ZFP36L2的小鼠脾脏（ZFP36L2条件性敲除小鼠，简称L2-cKO）所鉴定出的基因之间，重叠度极低。这一结果提示，ZFP36L2的靶标识别具有高度的组织特异性。
为明确调控该组织特异性的潜在因素，我们对脾脏来源的L2-cKO小鼠模型中的差异表达基因进行了表征；脾脏在人类与小鼠体内均高表达L2。我们分别采集了缺失ZFP36L2的L2-cKO小鼠与野生型（Wild Type, WT）小鼠的脾脏RNA样本，开展全转录组分析。野生型与L2-cKO小鼠脾脏的差异表达基因（Differential gene expression, DEG）分析显示，共筛选得到549个上调基因与603个下调基因。其中9个基因通过qPCR实验得到了验证。
实验整体设计：腺嘌呤尿嘧啶富集元件RNA结合蛋白（Adenine-uridine rich element-RNA-binding proteins, ARE-RBP）通常可稳定或降解其所结合的靶标转录本。该领域目前仍存在的核心挑战之一，在于阐明ARE-RBP的靶标识别特异性及其如何调控其生物学功能。我们分别采集了缺失ZFP36L2的L2-cKO小鼠与野生型WT小鼠的脾脏RNA样本，开展全转录组分析。