mrhl RNA, a Long Noncoding RNA, Negatively Regulates Wnt Signaling through Its Protein Partner Ddx5/p68 in Mouse Spermatogonial Cells
mrhl RNA, a Long Noncoding RNA, Negatively Regulates Wnt Signaling through Its Protein Partner Ddx5/p68 in Mouse Spermatogonial Cells
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DOI：
10.1128/mcb.00006-12
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发表时间：
2012-08-01
影响因子：
5.3
通讯作者：
Rao, Manchanahalli R. Satyanarayana
中科院分区：
文献类型：
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作者：
Arun, Gayatri;Akhade, Vijay Suresh;Rao, Manchanahalli R. Satyanarayana
减数分裂重组热点位点（mrhl）RNA是一种核富集的长非编码RNA，编码于小鼠基因组中，并在睾丸、肝脏、脾脏和肾脏中表达。在小鼠精原细胞来源的Gc 1-Spg细胞中，mrhl RNA沉默导致属于细胞粘附、细胞信号传导和发育以及分化的基因的表达受到干扰，其中许多是Wnt信号传导途径。一个加权的基因共表达网络产生了9个共表达模块，其中包括TCF 4，一个关键的转录因子参与Wnt信号。通过β-连环蛋白核定位、β-连环蛋白TCF 4相互作用、β-连环蛋白在Wnt靶基因启动子处的占据和TOP/FOP-荧光素酶测定证实了mrhl RNA下调后Wnt信号传导的激活。Northwestern blot和RNA pulldown实验证实Ddx 5/p68是mrhl RNA的相互作用蛋白之一。mrhl RNA的下调导致酪氨酸磷酸化的p68的细胞质易位。mrhl RNA和p68的同时下调阻止了β-连环蛋白的核转位。在Gc 1-Spg细胞中，经Wnt 3a处理后，mrhl RNA下调。这项研究表明，mrhl RNA通过与p68的相互作用在小鼠精原细胞中的Wnt信号转导中起负作用。
Meiotic recombination hot spot locus (mrhl) RNA is a nuclear enriched long noncoding RNA encoded in the mouse genome and expressed in testis, liver, spleen, and kidney. mrhl RNA silencing in Gc1-Spg cells, derived from mouse spermatogonial cells, resulted in perturbation of expression of genes belonging to cell adhesion, cell signaling and development, and differentiation, among which many were of the Wnt signaling pathway. A weighted gene coexpression network generated nine coexpression modules, which included TCF4, a key transcription factor involved in Wnt signaling. Activation of Wnt signaling upon mrhl RNA downregulation was demonstrated by beta-catenin nuclear localization, beta-catenin TCF4 interaction, occupancy of beta-catenin at the promoters of Wnt target genes, and TOP/FOP-luciferase assay. Northwestern blot and RNA pulldown experiments identified Ddx5/p68 as one of the interacting proteins of mrhl RNA. Downregulation of mrhl RNA resulted in the cytoplasmic translocation of tyrosine-phosphorylated p68. Concomitant downregulation of both mrhl RNA and p68 prevented the nuclear translocation of beta-catenin. mrhl RNA was downregulated on Wnt3a treatment in Gc1-Spg cells. This study shows that mrhl RNA plays a negative role in Wnt signaling in mouse spermatogonial cells through its interaction with p68.