Poly(A) tail length control in Saccharomyces cerevisiae occurs by message-specific deadenylation
Poly(A) tail length control in Saccharomyces cerevisiae occurs by message-specific deadenylation
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DOI：
10.1128/mcb.18.11.6548
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发表时间：
1998-11-01
影响因子：
5.3
通讯作者：
Sachs, AB
中科院分区：
文献类型：
--
作者：
Brown, CE;Sachs, AB
我们报道了新合成的mRNA聚(A)尾部被酿酒酵母的pab1p依赖性聚(A)核酸酶（PAN）成熟到精确的长度，这些结果为mRNA死基化的初始阶段提供了证据，该阶段是控制聚(A)尾部长度所必需的。在缺乏PAN的RNA 3'端加工提取物中，转录本的聚腺苷化长度超过200个核苷酸，相比之下，在含有PAN的提取物中，转录本的预期聚(A)尾部长度为60至80个核苷酸。PAN在体内控制聚(A)尾部长度的作用被发现在PAN缺乏的酵母菌株中产生的mrna具有更长的聚(A)尾部。有趣的是，发现野生型酵母菌株产生的转录本在其最大聚(A)尾长度上发生变化，而这种信息特异性长度控制在pan缺陷菌株中丢失。我们的数据支持一个模型，即mrna通过具有长尾（可能是默认长度）的3'端加工机制聚腺苷化，然后以pan依赖的方式，聚(a)尾部迅速成熟到特定于信息的长度。控制新表达mrna的聚(A)尾长度的能力可能是基因表达中重要的转录后调控步骤。
We report that newly synthesized mRNA poly(A) tails are matured to precise lengths by the Pab1p-dependent poly(A) nuclease (PAN) of Saccharomyces cerevisiae, These results provide evidence for an initial phase of mRNA deadenylation that is required for poly(A) tail length control. In RNA 3'-end processing extracts lacking PAN, transcripts are polyadenylated to lengths exceeding 200 nucleotides, By contrast, in extracts containing PAN, transcripts were produced with the expected wild-type poly(A) tail lengths of 60 to 80 nucleotides, The role for PAN in poly(A) tail length control in vivo was confirmed by the finding that mRNAs are produced with longer poly(A) tails in PAN-deficient yeast strains. Interestingly, wild-type yeast strains were found to produce transcripts which varied in their maximal poly(A) tail length, and this message-specific length control was lost in PAN-deficient strains. Our data support a model whereby mRNAs are polyadenylated by the 3'-end processing machinery with a long tail, possibly of default length, and then in a PAN-dependent manner, the poly(A) tails are rapidly matured to a message-specific length. The ability to control the length of the poly(A) tail for newly expressed mRNAs has the potential to be an important posttranscriptional regulatory step in gene expression.