Molecular analyses of two poly(A) site-processing factors that determine the recognition and efficiency of cleavage of the pre-mRNA.
Molecular analyses of two poly(A) site-processing factors that determine the recognition and efficiency of cleavage of the pre-mRNA.
复制标题
对决定前 mRNA 的识别和切割效率的两个 Poly(A) 位点加工因子进行分子分析。
DOI：
10.1128/mcb.11.5.2432-2438.1991
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发表时间：
1991
影响因子：
5.3
通讯作者：
Nevins,JR
中科院分区：
文献类型：
--
作者：
Gilmartin,GM;Nevins,JR
前体mRNA的Poly（A）位点加工需要多种核因子的参与。这些因子中的两个识别前mRNA中的特定序列并形成稳定的加工复合物。由于这些最初的相互作用可能是关键的聚（A）位点的识别和聚（A）位点的使用效率，我们已经表征了这些因素和它们与前mRNA相互作用的性质。AAUAAA特异性因子PF 2是一种大的多组分复合物，由至少5种分子大小为170至42 kDa的不同多肽组成。170-kDa多肽似乎介导与前mRNA的相互作用。因子CF 1为下游富含G+ U的元件提供特异性并稳定RNA上的PF 2相互作用，也是一种多组分复合物，但不如PF 2复杂。CF 1由分子大小为76、64和48 kDa的三种多肽组成。UV交联分析表明，64 kDa的多肽与RNA直接接触，依赖于富含G+ U的下游序列元件。此外，很明显，这些RNA-蛋白质相互作用受到涉及PF 2和CF 1的明显合作相互作用的影响，这种相互作用有助于poly（A）位点加工的效率。
Poly(A) site processing of a pre-mRNA requires the participation of multiple nuclear factors. Two of these factors recognize specific sequences in the pre-mRNA and form a stable processing complex. Since these initial interactions are likely critical for the recognition of the poly(A) site and the efficiency of poly(A) site use, we have characterized these factors and the nature of their interaction with the pre-mRNA. The AAUAAA specificity factor PF2 is a large, multicomponent complex composed of at least five distinct polypeptides ranging in molecular size from 170 to 42 kDa. The 170-kDa polypeptide appears to mediate interaction with the pre-mRNA. Factor CF1, which provides specificity for the downstream G+U-rich element and stabilizes the PF2 interaction on the RNA, is also a multicomponent complex but is less complex than PF2. CF1 is composed of three polypeptides of molecular sizes 76, 64, and 48 kDa. UV cross-linking assays demonstrate that the 64-kDa polypeptide makes direct contact with the RNA, dependent on the G+U-rich downstream sequence element. Moreover, it is clear that these RNA-protein interactions are influenced by the apparent cooperative interaction involving PF2 and CF1, interactions that contribute to the efficiency of poly(A) site processing.