The yeast CBP1 gene produces two differentially regulated transcripts by alternative 3'-end formation.
The yeast CBP1 gene produces two differentially regulated transcripts by alternative 3'-end formation.
复制标题
酵母 CBP1 基因通过选择性 3 末端形成产生两个差异调节的转录物。
DOI：
10.1128/mcb.9.10.4161-4169.1989
复制
发表时间：
1989
影响因子：
5.3
通讯作者：
Dieckmann,CL
中科院分区：
文献类型：
--
作者：
Mayer,SA;Dieckmann,CL
CBP 1是一个酵母核基因，编码一种线粒体蛋白，稳定细胞色素b（cob）前体mRNA的5′端。细胞色素是呼吸链复合体III中唯一经呼吸道合成的成分。由于该复合物的核编码亚基在转录水平上受到分解代谢产物抑制的调控，我们推测CBP 1可能受到类似的调控。为了验证CBP 1的转录调节可以协调细胞色素mRNA稳定性的增加和核编码复合物III亚基产生的增加，我们描述了在不可发酵碳源上去阻遏过程中CBP 1 mRNA丰度的变化。用CBP 1的cRNA探针对去阻遏酵母细胞的Poly（A）+RNA进行了北方（RNA）分析。1.3-kb的mRNA缺少2.2-kb的mRNA的3′端约900个核苷酸，而2.2-kb的mRNA编码CBP 1编码序列的羧基端250个氨基酸残基。从缺失-插入突变体的CBP 1和从过表达CBP 1 mRNA的菌株中分离的RNA的北方分析表明，这两种mRNA都是从CBP 1基因转录的。此外，我们证明了两种CBP 1 mRNA的水平受到生长培养基中碳源的间接调控。这是第一次描述一个酵母基因，其中两个转录本可以编码具有明显不同的编码特性的蛋白质，通过交替的3′端形成。
CBP1is a yeast nuclear gene encoding a mitochondrial protein that stabilizes the 5′ end of cytochromeb (cob)pre-mRNA. Cytochromebis the only mitochondrially synthesized component of the respiratory chain complex III. Since the nuclearly encoded subunits of this complex are regulated at the transcriptional level by catabolite repression, we hypothesized thatCBP1might be similarly regulated. To test the idea that transcriptional regulation ofCBP1could coordinate an increase in cytochromebmRNA stability with an increase in nuclearly encoded complex III subunit production, we characterized the change in abundance ofCBP1mRNA during derepression on a nonfermentable carbon source. Poly(A)+RNA from derepressed yeast cells was examined by Northern (RNA) analyses with cRNA probes fromCBP1.Both 2.2- and 1.3-kilobase (kb) transcripts were detected. The 1.3-kb mRNA lacked approximately 900 nucleotides of the 3′ end of the 2.2-kb mRNA, which encodes the carboxyl-terminal 250 amino acid residues of theCBP1coding sequence. Northern analyses of RNA isolated from deletion-insertion mutants ofCBP1and from strains that overexpressCBP1mRNA demonstrated that both mRNAs were transcribed from theCBP1gene. Furthermore, we demonstrated that the levels of the twoCBP1mRNAs were reciprocally regulated by the carbon source in the growth medium. This is the first description of a yeast gene from which two transcripts that can encode proteins with distinctly different coding properties are generated by alternative 3′-end formation.