描述两个cDNA克隆的丙酮酸脱氢酶E1β亚基及其监管三羧酸cycle-deficient纤维母细胞。
文章的细节
-
引用
复制到剪贴板 -
嗯TL, Casazza JP,嗯JW,欧美,BJ的歌
描述两个cDNA克隆的丙酮酸脱氢酶E1β亚基及其监管三羧酸cycle-deficient纤维母细胞。
生物化学杂志。1990年8月5日;265 (22):13320 - 6。
- PubMed ID
-
2376596 (在PubMed]
- 文摘
-
两个不同类型的cDNA克隆编码的丙酮酸脱氢酶(PDH) E1β亚基是脱离人类的肝脏λgt11 cDNA库和特征。这些cDNA克隆有相同的核苷酸序列PDH E1β蛋白编码区,但有不同的长度和序列的3 '非翻译区。较小的cDNA有一个不寻常的聚腺苷酸化信号在其蛋白质编码区。PDH E1的cDNA-deduced蛋白β亚基透露359氨基酸残基的前体蛋白(39223)先生329年和一个成熟的蛋白质残基先生(35894),分别。两个互补共享高氨基酸序列相似性与隔绝人类包皮(小池百合子,株式会社,太。浦田,Y。Kagawa, Y。小池百合子,m (1988) Proc。国家的。学会科学。41 - 45美国85年,除了三个区域移码突变。 These changes led to dramatic alterations in the local net charges and predicted protein conformation. One of the different sequences in the protein coding region of liver cDNA (nucleotide position 452-752) reported here was confirmed by sequencing the region after amplification of cDNA prepared from human skin fibroblasts by the polymerase chain reaction. Southern blot analysis verified simple patterns of hybridization with E1 beta cDNA, indicating that the PDH E1 beta subunit gene is not a member of a multigene family. The mechanisms of differential expression of the PDH E1 alpha and E1 beta subunits were also studied in established fibroblast cell lines obtained from patients with Leigh's syndrome and other forms of congenital lactic acidosis. In Northern blot analyses for PDH E1 alpha and E1 beta subunits, no apparent differences were observed between two Leigh's syndrome and the control fibroblasts studied: one species of PDH E1 alpha mRNA and three species of E1 beta mRNA were observed in all the cell lines examined. However, in one tricarboxylic acid cycle deficient fibroblast cell line, which has one-tenth of the normal enzyme activity, the levels of immunoreactive PDH E1 alpha and E1 beta subunits were markedly decreased as assessed by immunoblot analyses. These data indicated a regulatory mutation caused by either inefficient translation of E1 alpha and E1 beta mRNAs into protein or rapid degradation of both subunits upon translation. In contrast, the PDH E1 alpha and E1 beta subunits in two fibroblast cell lines from Leigh's syndrome patients appeared to be normal as judged by 1) enzyme activity, 2) mRNA Northern blot, 3) genomic DNA Southern blot, and 4) immunoblot analyses indicating that the lactic acidosis seen in these patients did not result from a single defect in either of these E1 alpha and E1 beta subunits of the PDH complex.