hnRNP A1 selectively interacts through its Gly-rich domain with different RNA-binding proteins
hnRNP A1 selectively interacts through its Gly-rich domain with different RNA-binding proteins
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DOI：
10.1006/jmbi.1996.0324
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发表时间：
1996-06-14
影响因子：
5.6
通讯作者：
Biamonti, G
中科院分区：
文献类型：
--
作者：
Cartegni, L;Maconi, M;Biamonti, G
异质核核糖核蛋白（hnRNPs）是一种丰富的核多肽，很可能参与mrna前加工的不同步骤。蛋白A1 （34 kDa）是hnRNP家族的重要成员，似乎通过调节RNA二级结构和在剪接位点选择和外显子跳变/包合中拮抗一些剪接因子（SR蛋白）起作用。A1在RNA核胞质转运中的作用也被提出。这些活性可能不仅取决于蛋白质的rna结合特性，还取决于特定的蛋白质-蛋白质相互作用。在这里，我们报道A1确实可以选择性地相互作用，在体外，与自身和。与其他hnRNP基本“核心”蛋白。这种选择性结合完全由富含gly的c端结构域介导，其中可以设想由疏水重复构成的新型蛋白质结合基序。同样的结构域是必要的和充分的，以促进体内特定的相互作用，通过酵母双杂交试验。此外，还有吗？与一些SR蛋白的体外相互作用也被观察到。这些观察结果表明，不同和特定的蛋白-蛋白相互作用可能有助于hnRNP A1蛋白在mRNA成熟中的不同功能。(C) 1996学术出版社有限公司
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are abundant nuclear polypeptides, most likely involved in different steps of pre-mRNA processing. Protein A1 (34 kDa), a prominent member of the hnRNP family, seems to act by modulating the RNA secondary structure and by antagonizing some splicing factors (SR proteins) in splice-site selection and exon skipping/inclusion. A role of A1 in the nucleo-cytoplasmic transport of RNA has also been proposed. These activities might depend not only on the RNA-binding properties of the protein but also on specific protein-protein interactions. Here we report that A1 can indeed selectively interact, in vitro, both with itself and. with other hnRNP basic ''core'' proteins. Such selective binding is mediated exclusively by the Gly-rich C-terminal domain, where a novel protein-binding motif constituted by hydrophobic repeats can be envisaged. The same domain is necessary and sufficient to promote specific interaction in vivo, as assayed by the yeast two-hybrid assay. Moreover, an ii? vitro interaction with some SR proteins was also observed. These observations suggest that diverse and specific protein-protein interactions might contribute to the different functions of the hnRNP A1 protein in mRNA maturation. (C) 1996 Academic Press Limited