Molecular cloning of mevalonate kinase and regulation of its mRNA levels in rat liver.
Molecular cloning of mevalonate kinase and regulation of its mRNA levels in rat liver.
复制标题
甲羟戊酸激酶的分子克隆及其在大鼠肝脏中 mRNA 水平的调节。
DOI：
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发表时间：
1990
影响因子：
11.1
通讯作者：
Stephen T. Mosley
中科院分区：
文献类型：
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作者：
Richard D. Tanaka;Lynn Y. Lee;Beverly L. Schafer;V. Kratunis;William A. Mohler;Gordon W. Robinson;Stephen T. Mosley
甲羟戊酸激酶[ATP：（R）-甲羟戊酸5-磷酸转移酶，EC 2.7.1.36]可能是胆固醇生物合成途径中的调节位点，并且编码该酶的基因中的突变被认为引起遗传疾病甲羟戊酸尿症。为了表征这种酶，用单特异性抗体筛选大鼠肝脏cDNA文库，并分离出编码甲羟戊酸激酶的1.7千碱基cDNA克隆。确定了完整的DNA序列，最长的开放阅读框编码的蛋白质含有395个氨基酸，推导的分子量为41，990。通过酵母中酶活性的表达和从测序纯化的大鼠甲羟戊酸激酶获得的蛋白质序列数据确认cDNA克隆的鉴定。推导的甲羟戊酸激酶的氨基酸序列包含蛋白激酶中发现的ATP结合位点的基序，并且它也显示出与酵母RAR 1蛋白的序列同源性。大鼠肝脏中甲羟戊酸激酶mRNA的大小约为2个酶。用含有降胆固醇剂的饮食治疗引起甲羟戊酸激酶活性和mRNA水平的增加，而含有5%胆固醇的饮食降低了酶活性和mRNA的水平。这些数据表明，在大鼠肝脏中的酶活性的长期调节是由甲羟戊酸激酶mRNA水平的变化控制。
Mevalonate kinase [ATP:(R)-mevalonate 5-phosphotransferase, EC 2.7.1.36] may be a regulatory site in the cholesterol biosynthetic pathway, and a mutation in the gene coding for this enzyme is thought to cause the genetic disease mevalonic aciduria. To characterize this enzyme, a rat liver cDNA library was screened with a monospecific antibody, and a 1.7-kilobase cDNA clone coding for mevalonate kinase was isolated. The complete DNA sequence was determined, and the longest open reading frame coded for a protein containing 395 amino acids with a deduced molecular weight of 41,990. Identification of the cDNA clone was confirmed by expression of enzyme activity in yeast and by protein sequence data obtained from sequencing purified rat mevalonate kinase. The deduced amino acid sequence of mevalonate kinase contained a motif for the ATP-binding site found in protein kinases, and it also showed sequence homology to the yeast RAR1 protein. The size of mevalonate kinase mRNA in rat liver was approximately 2 kilobases. Treatment with diets containing cholesterol-lowering agents caused an increase in both mevalonate kinase activity and mRNA levels, whereas diets containing 5% cholesterol lowered the levels of both enzyme activity and mRNA. These data indicate that long-term regulation of enzyme activity in rat liver is controlled by changes in the levels of mevalonate kinase mRNA.