The SRP9/14 subunit of the human signal recognition particle binds to a variety of Alu-like RNAs and with higher affinity than its mouse homolog
The SRP9/14 subunit of the human signal recognition particle binds to a variety of Alu-like RNAs and with higher affinity than its mouse homolog
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DOI：
10.1093/nar/25.2.318
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发表时间：
1997-01-15
影响因子：
14.9
通讯作者：
Strub, K
中科院分区：
文献类型：
--
作者：
Bovia, F;Wolff, N;Strub, K
先前已经发现信号识别颗粒（SRP）的异二聚体亚基SRP 9/14在体外与scAlu和scB 1 RNA结合，并且在类胶质细胞中以远远超过SRP的量存在。在这里，我们表明人和小鼠SRP 9/14以高亲和力与不同进化年龄的其他类胶质细胞RNA结合，包括神经元特异性BC 200 RNA，不同的RNA-蛋白质复合物的相对解离常数与Alu RNA种类和7SL RNA之间的进化距离成反比。此外，人SRP 9/14以比小鼠SRP 9/14更高的亲和力与分析的所有RNA结合，并且这种差异不能通过在类人SRP 14中存在的额外的C-末端结构域来解释。SRP 9/14和Alu样RNA之间的高亲和力相互作用的保守性强烈表明这些Alu样RNP存在于体内并且它们具有细胞功能。观察到人SRP 9/14比其小鼠对应物更好地结合远亲Alu RNA，例如最近转座的元件，表明，SRP 9/14的特定的过量可能在控制Alu扩增中起作用，而不是在补偿SRP组装和功能中的缺陷。
The heterodimeric subunit, SRP9/14, of the signal recognition particle (SRP) has previously been found to bind to scAlu and scB1 RNAs in vitro and to exist in large excess over SRP in anthropoid cells, Here we show that human and mouse SRP9/14 bind with high affinities to other Alu-like RNAs of different evolutionary ages including the neuron-specific BC200 RNA, The relative dissociation constants of the different RNA-protein complexes are inversely proportional to the evolutionary distance between the Alu RNA species and 7SL RNA. In addition, the human SRP9/14 binds with higher affinity than mouse SRP9/14 to all RNAs analyzed and this difference is not explained by the additional C-terminal domain present in the anthropoid SRP14. The conservation of high affinity interactions between SRP9/14 and Alu-like RNAs strongly indicates that these Alu-like RNPs exist in vivo and that they have cellular functions, The observation that human SRP9/14 binds better than its mouse counterpart to distantly related Alu RNAs, such as recently transposed elements, suggests that the anthropoid-specific excess of SRP9/14 may have a role in controlling Alu amplification rather than in compensating a defect in SRP assembly and functions.