McIntosh E M, Gadsden M H, Haynes R H
Mol Gen Genet. 1986 Sep;204(3):363-6. doi: 10.1007/BF00331011.
We have examined the pattern of transcription exhibited by four genes in the dTTP biosynthetic pathway of Saccharomyces cerevisiae. Consistent with the results reported previously by Storms et al. (1984), the TMP1 (or CDC21) gene encoding thymidylate synthase was found to be transcribed in a periodic manner during the cell cycle with maximal mRNA levels occurring just prior to the onset of DNA replication. Three other genes in this pathway DCD1, DUT1 and DFR1 encoding dCMP deaminase, dUTP pyrophosphatase and dihydrofolate reductase, respectively, exhibited relatively constant levels of transcription throughout the cell cycle. These results, particularly for DFR1, are in marked contrast with those obtained in other eukaryotic systems which have suggested that, in general, genes encoding enzymes involved in DNA precursor synthesis are subject to cell cycle regulation. Thus, periodic transcription is not a property common to all genes involved in DNA replication in this eukaryote.
我们研究了酿酒酵母dTTP生物合成途径中四个基因的转录模式。与Storms等人（1984年）之前报道的结果一致，发现编码胸苷酸合成酶的TMP1（或CDC21）基因在细胞周期中呈周期性转录，最大mRNA水平出现在DNA复制开始之前。该途径中的其他三个基因DCD1、DUT1和DFR1分别编码dCMP脱氨酶、dUTP焦磷酸酶和二氢叶酸还原酶，在整个细胞周期中表现出相对恒定的转录水平。这些结果，特别是DFR1的结果，与在其他真核系统中获得的结果形成了显著对比，其他真核系统表明，一般来说，参与DNA前体合成的酶的编码基因受细胞周期调控。因此，周期性转录并非该真核生物中所有参与DNA复制的基因所共有的特性。
