Nakajima H, Noguchi T, Hamaguchi T, Tomita K, Hanafusa T, Kono N, Tanaka T, Kuwajima M, Matsuzawa Y
Second Department of Internal Medicine, Osaka University Medical School, Suita, Japan.
Biochem J. 1994 Oct 15;303 ( Pt 2)(Pt 2):449-53. doi: 10.1042/bj3030449.
Molecular cloning of the 5' part of mouse phosphofructokinase-M cDNA was performed. In the 46 cDNA clones isolated, there were two classes of 5' untranslated sequences. One had an EcoRI site within its 5' untranslated sequence. This showed 83.0% similarity with human type B mRNA for phosphofructokinase-M. The other lacked an EcoRI site, showing 92.9% similarity with human type C mRNA. Using the reverse-transcription PCR technique, we found that the transcript with an EcoRI site was exclusively expressed in cardiac and skeletal muscles, while that without an EcoRI site was expressed in all the mouse tissues examined. The results suggested that the mouse phosphofructokinase-M gene was transcribed through alternative splicing by the multiple promoters. This transcription mechanism was considered to be evolutionarily conserved. The level of phosphofructokinase-M gene expression in mouse cardiac and skeletal muscles decreased in the ketotic diabetic state. Although the regulatory mechanism and the physiological significance are not fully known, this would indicate that phosphofructokinase-M gene transcripts are affected during the diabetic state.
进行了小鼠磷酸果糖激酶-M cDNA 5' 端部分的分子克隆。在分离出的46个cDNA克隆中，有两类5' 非翻译序列。一类在其5' 非翻译序列中有一个EcoRI位点。它与人类磷酸果糖激酶-M的B型mRNA显示出83.0% 的相似性。另一类缺乏EcoRI位点，与人类C型mRNA显示出92.9% 的相似性。使用逆转录PCR技术，我们发现具有EcoRI位点的转录本仅在心肌和骨骼肌中表达，而没有EcoRI位点的转录本在所有检测的小鼠组织中均有表达。结果表明，小鼠磷酸果糖激酶-M基因通过多个启动子经可变剪接进行转录。这种转录机制被认为在进化上是保守的。在酮症糖尿病状态下，小鼠心肌和骨骼肌中磷酸果糖激酶-M基因的表达水平降低。尽管调控机制和生理意义尚不完全清楚，但这表明磷酸果糖激酶-M基因转录本在糖尿病状态下受到影响。
