Isolation and characterization of brain Y-box protein: developmentally regulated expression, polyribosomal association and dendritic localization
Isolation and characterization of brain Y-box protein: developmentally regulated expression, polyribosomal association and dendritic localization
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DOI：
10.1016/s0169-328x(03)00328-0
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发表时间：
2003-10-21
期刊：
影响因子：
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通讯作者：
Anzai, K
中科院分区：
文献类型：
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作者：
Funakoshi, T;Kobayashi, S;Anzai, K
Y盒蛋白是DNA和RNA结合蛋白，在转录和翻译水平上控制特异性基因表达。特别是在生殖细胞中，已经报道Y盒蛋白结合到父体或母体mRNA以形成mRNP，使其不能翻译并控制细胞成熟。在这项研究中，我们克隆了一个Y-盒蛋白的cDNA从大鼠脑。该蛋白的氨基酸序列与其他几种Y盒蛋白非常相似，我们将其命名为rBYB 1（大鼠脑Y盒蛋白1）。rBYB 1在出生前和出生后早期的脑细胞质中大量表达，然后随着脑发育下降到成人水平。此外，我们发现rBYB 1在蔗糖密度梯度上分布在多聚核糖体和非多聚核糖体（mRNP）部分中，并且在较高密度的部分中通过RNA与多聚核糖体结合。此外，rBYB 1定位于原代海马神经元的树突。我们比较了这些蔗糖梯度和细胞内rBYB 1定位结果与脆性X智力低下蛋白（FMRP），这是已知的mRNA结合和多核糖体相关的翻译调节分布在神经元树突。我们的研究结果表明，在出生前和新生动物的大脑中，rBYB 1可能在存储和/或翻译调节的mRNA参与出生后大脑的快速发展，并在成熟的神经元，它也可能参与控制树突中的蛋白质合成。(C)2003 Elsevier B. V.保留所有权利。
Y-box proteins are DNA- and RNA-binding proteins and control specific gene expression at both transcriptional and translational levels. Particularly in germ cells, it has been reported that Y-box proteins bind to paternal or maternal mRNAs to form mRNPs, mask them from translation and control cell maturation. In this study, we cloned cDNA for a Y-box protein from rat brain. A deduced amino acid sequence of the protein was very similar to that of several other Y-box proteins, and we termed the protein rBYB1 (rat brain Y-box protein 1). rBYB1 was found to be considerably expressed in the cytoplasm of pre- and early postnatal brains, and then decreased to adult levels with brain development. Further, we found rBYB1 to be distributed in both polyribosomal and nonpolyribosomal (mRNP) fractions on a sucrose density gradient, and to be associated with polyribosomes via RNA in the higher-density fractions. Moreover, rBYB1 was localized in dendrites of the primary hippocampal neurons. We compared these sucrose gradient and intracellular rBYB1 localization results with those for fragile X mental retardation protein (FMRP), which is known to be an mRNA-binding and polyribosome-associating translational regulator distributed in neuronal dendrites. Our results suggest that in the brain of prenatal and newborn animals, rBYB1 may function in storage and/or translational regulation of mRNAs involved in the rapid progress of the postnatal brain, and in mature neurons, it may also participate in the control of protein synthesis in dendrites. (C) 2003 Elsevier B.V. All rights reserved.