TESTIS-BRAIN RNA-BINDING PROTEIN, A TESTICULAR TRANSLATIONAL REGULATORY RNA-BINDING PROTEIN, IS PRESENT IN THE BRAIN AND BINDS TO THE 3'-UNTRANSLATED REGIONS OF TRANSPORTED BRAIN MESSENGER-RNAS
TESTIS-BRAIN RNA-BINDING PROTEIN, A TESTICULAR TRANSLATIONAL REGULATORY RNA-BINDING PROTEIN, IS PRESENT IN THE BRAIN AND BINDS TO THE 3'-UNTRANSLATED REGIONS OF TRANSPORTED BRAIN MESSENGER-RNAS
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DOI：
10.1095/biolreprod53.3.707
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发表时间：
1995-09-01
影响因子：
3.6
通讯作者：
HECHT, NB
中科院分区：
文献类型：
--
作者：
HAN, JR;GU, W;HECHT, NB
以往的研究表明，睾丸中的一种磷蛋白与小鼠鱼精蛋白2mRNA(MP2)的3‘非翻译区(UTR)中含有两个高度保守的元件Y和H的转录本c结合，并在体外抑制其翻译。当用从七种不同小鼠组织制备的细胞质提取物进行凝胶延迟分析时，我们发现除了睾丸外，大脑还含有一种与转录本c结合的蛋白质。睾丸和大脑蛋白质都只在其线粒体后提取物的非多聚体部分中被发现，根据许多标准，睾丸和大脑蛋白质似乎是相同的：它们与转录本c形成的复合体在天然凝胶中具有相同的流动性，相同的最佳pH，相同的对盐浓度增加的不稳定性，相同的层析性质，从UV交联判断的相同的分子大小，以及通过V8消化UV交联的蛋白质-RNA复合体揭示的相同的肽图谱。除了与MP2的3‘端非编码区相同的保守序列结合外，来自睾丸和大脑的磷蛋白，以下称为睾丸-脑RNA结合蛋白(TB-RBP)，也特异性地与脑Tau mRNA的3’端非编码区的类似序列结合。由于TB-RBP与睾丸中几个翻译调控的mRNA3‘端非编码区结合，而且许多转运的脑内mRNAs也含有相同的保守结合元件，因此我们认为TB-RBP在脑和睾丸中参与了mRNA的储存、转位和/或定位。
Previous studies have demonstrated that a phosphoprotein in testis binds to transcript c, a sequence containing two highly conserved elements, Y and H, in the 3' untranslated region (UTR) of mouse protamine 2 mRNA (mP2) and represses its translation in vitro. When gel-retardation assays were performed with cytoplasmic extracts prepared from seven different mouse tissues, we found that brain in addition to testis contains a protein that binds to transcript c. Both the testis and brain proteins are found exclusively in the nonpolysomal fractions of their postmitochondrial extracts, The testis and brain proteins appear to be identical according to numerous criteria: the complexes they form with transcript c have identical mobility in native gels, identical optimal pH, identical lability to increased salt concentrations, identical chromatographic properties, identical molecular sizes as judged from UV crosslinking, and identical peptide mapping as revealed by V8 digestion of the UV crosslinked protein-RNA complexes. in addition to binding to the same conserved sequence in the 3'UTR of mP2, the phosphoprotein from testis and bra in, hereafter called testis-brain RNA-binding protein (TB-RBP), also specifically binds to a similar sequence in the 3'UTR of brain Tau mRNA. Since TB-RBP binds to the 3'UTRs of several translationally regulated mRNAs in testis and since numerous transported brain mRNAs also contain the same conserved binding elements, we propose that TB-RBP plays a role in mRNA storage, translocation, and/or localization in brain and testis.