NUCLEOTIDE-SEQUENCE OF MURINE ORNITHINE DECARBOXYLASE MESSENGER-RNA
NUCLEOTIDE-SEQUENCE OF MURINE ORNITHINE DECARBOXYLASE MESSENGER-RNA
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DOI：
10.1073/pnas.82.6.1673
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
NATHANS, D
中科院分区：
文献类型：
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作者：
KAHANA, C;NATHANS, D
鸟氨酸脱羧酶（OrnDCase; L-ornithine carboxy-lase, EC 4.1.1.17）是哺乳动物细胞中多胺生物合成的第一个也是限速酶。在细胞生长过程中，这种酶受其mRNA和蛋白质水平的快速变化所调节。为了探索这些变化的分子基础，从小鼠细胞中克隆了主要的2.4千碱基OrnDCase mRNA的全长c[互补]DNA拷贝，并确定了其序列。该cDNA包含来自OrnDCase mRNA的2465个核苷酸，包括全长737个核苷酸的5”非编码段，全长1383个核苷酸的编码段，末端是一个TAG三联体，全长342个核苷酸的3”非编码段。该编码蛋白由461个氨基酸残基组成，分子量为51,105，具有酪蛋白激酶II磷酸化的潜在位点。在异常长的5”先导序列中，有4个ATG三联体，每个ATG三联体后面都有一个同相终止信号；这些上游ATG的存在可以解释先前报道的OrnDCase mRNA较低的体外翻译活性。用定义的OrnDCase编码序列探测小鼠基因组DNA的限制性酶切文摘，揭示了一个多成员的OrnDCase相关基因家族。
Ornithine decarboxylase (OrnDCase; L-ornithine carboxy-lase, EC 4.1.1.17) is the 1st and rate-limiting enzyme in the biosynthesis of polyamines in mammalian cells. During cell growth the enzyme is regulated by rapid changes in the level of its mRNA and protein. To explore the molecular basis of these changes, a full-length c[complementary]DNA copy of the major 2.4-kilobase OrnDCase mRNA was cloned from mouse cells and its sequence determined. The cDNA contains 2465 nucleotides derived from OrnDCase mRNA, consisting of a 737-nucleotide-long 5'' noncoding segment, a coding segment of 1383 nucleotides terminated by a TAG triplet, and a 342-nucleotide 3'' noncoding segment. The encoded protein of 461-amino acid residues has a MW of 51,105 and has a potential site for phosphorylation by casein kinase II. In the unusually long 5'' leader sequence, there are 4 ATG triplets, each of which followed by an in-phase termination signal; the presence of these upstream ATG could explain the low in vitro translational activity of OrnDCase mRNA reported earlier. A restriction digest of mouse genomic DNA was probed with a defined OrnDCase coding sequence, revealing a multimembered family of OrnDCase-related genes.