Cloning and characterization of PDK4 on 7q21.3 encoding a fourth pyruvate dehydrogenase kinase isoenzyme in human
Cloning and characterization of PDK4 on 7q21.3 encoding a fourth pyruvate dehydrogenase kinase isoenzyme in human
复制标题
DOI：
10.1074/jbc.271.37.22376
复制
发表时间：
1996-09-13
影响因子：
4.8
通讯作者：
Prochazka, M
中科院分区：
文献类型：
--
作者：
Rowles, J;Scherer, SW;Prochazka, M
丙酮酸脱氢酶激酶（PDK）的不同同工酶通过E1α亚基的磷酸化来抑制线粒体丙酮酸脱氢酶复合物，从而有助于葡萄糖代谢的调节。通过在皮马印第安人中与胰岛素抵抗和非胰岛素依赖型糖尿病相关的 7q21.3-q22.1 区域中进行定位克隆，Fee 鉴定了一个编码额外人类 PDR 亚型的基因，其与其他哺乳动物 PDK 的氨基酸序列同一性 (>65%) 证明了这一点，并通过重组蛋白的生化分析得到了证实。我们对该基因（称为 PDK4）在胰岛素抵抗和胰岛素敏感方面进行了详细的比较分析皮马印第安人，并在两个受试者群体中检测到了频率相当的五种 DNA 变异。使用定量逆转录聚合酶链反应，我们发现启动子和 5'-非翻译区中鉴定的变异与骨骼肌和脂肪组织中 mRNA 水平的差异无关。我们得出的结论是，PDK4 的改变不太可能是在皮马印第安人中观察到的 7q21.3-q22.1 连锁的分子基础。有关 PDK4 的基因组组织和启动子序列的信息将有助于研究线粒体蛋白激酶家族的其他成员，这些成员对葡萄糖代谢的调节很重要。
Different isoenzymes of pyruvate dehydrogenase kinase (PDK) inhibit the mitochondrial pyruvate dehydrogenase complex by phosphorylation of the E1 alpha subunit, thus contributing to the regulation of glucose metabolism. By positional cloning in the 7q21.3-q22.1 region linked with insulin resistance and non-insulin-dependent diabetes mellitus in the Pima Indians, Fee identified a gene encoding an additional human PDR isoform, as evidenced by its amino acid sequence identity (>65%) with other mammalian PDKs, and confirmed by biochemical analyses of the recombinant protein.We performed detailed comparative analyses of the gene, termed PDK4, in insulin-resistant and insulin-sensitive Pima Indians, and detected five DNA variants with comparable frequencies in both subject groups. Using quantitative reverse transcription polymerase chain reaction, we found that the variants identified in the promoter and 5'-untranslated region did not correlate with differences in mRNA level in skeletal muscle and adipose tissue. We conclude that alterations in PDK4 are unlikely to be the molecular basis underlying the observed linkage at 7q21.3-q22.1 in the Pima Indians. Information about the genomic organization and promoter sequences of PDK4 will be useful in studies of other members of this family of mitochondrial protein kinases that are important for the regulation of glucose metabolism.