Identification of two cis-acting elements that independently regulate the length of poly(A) on Xenopus albumin pre-mRNA.
Identification of two cis-acting elements that independently regulate the length of poly(A) on Xenopus albumin pre-mRNA.
复制标题
鉴定两个独立调节非洲爪蟾白蛋白前体 mRNA 上聚腺苷酸长度的顺式作用元件。
DOI：
10.1017/s1355838298971837
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Schoenberg,DR
中科院分区：
文献类型：
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作者：
DasGupta,J;Gu,H;Chernokalskaya,E;Gao,X;Schoenberg,DR
与迄今为止研究的大多数真核生物mRNA不同，非洲爪蟾血清白蛋白mRNA具有短（17个残基）、离散的poly（A）尾。我们最近报道，这种短的poly（A）尾是由于白蛋白前体mRNA上poly（A）长度的调节所致。本研究的目的是找到负责这一顺式作用元件，聚（A）限制元件或PLE。白蛋白基因3′端的第13外显子连接白蛋白cDNA，当转染小鼠成纤维细胞时，白蛋白小基因产生含<20 nt poly（A）的mRNA。这一结果表明，这两个顺式作用序列，调节聚（A）的长度是在这个构建体，和多聚（A）的长度的核调控是保守的脊椎动物之间。用合成的多聚腺苷酸化元件（SPA）替换白蛋白基因的末端53 bp和3′侧翼区后，Poly（A）长度调节得以保留。相反，将白蛋白基因末端53 bp的白蛋白基因序列和3′侧翼序列融合到人β-珠蛋白基因上，产生具有200个残基的poly（A）尾的珠蛋白mRNA。这些数据表明PLE位于参与白蛋白前mRNA 3′加工的序列元件的上游。将白蛋白内含子14、外显子15和3′侧翼序列融合到β-珠蛋白基因后，Poly（A）长度调节恢复。我们证明，外显子15包含两个PLEs，可以独立地调节poly（A）的长度。
Unlike most eukaryotic mRNAs studied to date, Xenopus serum albumin mRNA has a short (17-residue), discrete poly(A) tail. We recently reported that this short poly(A) tail results from regulation of the length of poly(A) on albumin pre-mRNA. The purpose of the present study was to locate the cis-acting element responsible for this, the poly(A)-limiting element or PLE. An albumin minigene consisting of albumin cDNA joined in exon 13 to the 3′ end of the albumin gene produced mRNA with <20 nt poly(A) when transfected into mouse fibroblasts. This result indicates both that cis-acting sequences that regulate poly(A) length are within this construct, and that nuclear regulation of poly(A) length is conserved between vertebrates. Poly(A) length regulation was retained after replacing the terminal 53 bp and 3′ flanking region of the albumin gene with a synthetic polyadenylation element (SPA). Conversely, fusing albumin gene sequence spanning the terminal 53 bp of the albumin gene and 3′ flanking sequence onto the human β-globin gene yielded globin mRNA with a 200-residue poly(A)tail. These data indicate that the PLE resides upstream of the sequence elements involved in albumin pre-mRNA 3′ processing. Poly(A) length regulation was restored upon fusing a segment bearing albumin intron 14, exon 15, and 3′ flanking sequence onto the β-globin gene. We demonstrate that exon 15 contains two PLEs that can act independently to regulate the length of poly(A).