A novel endonuclease activity associated with the Arabidopsis ortholog of the 30-kDa subunit of cleavage and polyadenylation specificity factor.
A novel endonuclease activity associated with the Arabidopsis ortholog of the 30-kDa subunit of cleavage and polyadenylation specificity factor.
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DOI：
10.1093/nar/gkm457
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发表时间：
2007
影响因子：
14.9
通讯作者：
Hunt AG
中科院分区：
文献类型：
--
作者：
Addepalli B;Hunt AG
信使RNA的多腺苷酸化由真核生物中保守的多亚基复合物介导。这些蛋白质中最有趣的是切割和多聚腺苷酸化特异性因子（CPSF 30）的30 kDa亚基。在这项研究中，拟南芥CPSF 30直系同源物，AtCPSF 30，其特征在于。这种蛋白质具有意想不到的核酸内切活性，这是明显的切口和降解线性以及环状单链RNA的能力。AtCPSF 30的核酸内切作用使RNA 3′端带有羟基，因为它们可以被RNA连接酶用[32 P]-胞苷-3 ′，5 ′-二磷酸标记。突变的蛋白质的三个CCCH锌指基序的第一个废除AtCPSF 30的RNA结合，但对核酸酶活性没有明显的影响。相反，第三锌指基序的突变消除了蛋白质的核酸酶活性，并对RNA结合有适度的影响。另一个拟南芥多聚腺苷酸化因子亚基AtFip 1（V）的N端结构域显著抑制AtCPSF 30的核酸酶活性，但对蛋白质的RNA结合活性有轻微的负面影响。这些结果表明，AtCPSF 30是一个可能的加工核酸内切酶，它的行动是协调通过与Fip 1的相互作用。
The polyadenylation of messenger RNAs is mediated by a multi-subunit complex that is conserved in eukaryotes. Among the most interesting of these proteins is the 30-kDa-subunit of the Cleavage and Polyadenylation Specificity Factor, or CPSF30. In this study, the Arabidopsis CPSF30 ortholog, AtCPSF30, is characterized. This protein possesses an unexpected endonucleolytic activity that is apparent as an ability to nick and degrade linear as well as circular single-stranded RNA. Endonucleolytic action by AtCPSF30 leaves RNA 3′ ends with hydroxyl groups, as they can be labeled by RNA ligase with [32P]-cytidine-3′,5′-bisphosphate. Mutations in the first of the three CCCH zinc finger motifs of the protein abolish RNA binding by AtCPSF30 but have no discernible effects on nuclease activity. In contrast, mutations in the third zinc finger motif eliminate the nuclease activity of the protein, and have a modest effect on RNA binding. The N-terminal domain of another Arabidopsis polyadenylation factor subunit, AtFip1(V), dramatically inhibits the nuclease activity of AtCPSF30 but has a slight negative effect on the RNA-binding activity of the protein. These results indicate that AtCPSF30 is a probable processing endonuclease, and that its action is coordinated through its interaction with Fip1.
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影响因子：
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作者：
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通讯作者：
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影响因子：
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