Wathelet M, Moutschen S, Defilippi P, Cravador A, Collet M, Huez G, Content J
Eur J Biochem. 1986 Feb 17;155(1):11-7. doi: 10.1111/j.1432-1033.1986.tb09452.x.
Among the various proteins which are induced when human cells are treated with interferon, a predominant protein of unknown function, with molecular mass 56 kDa, has been observed. With the aim of exploring the molecular basis of the regulation of this protein and of its mRNA, in order to understand its biological function and its possible contribution to the various antiviral and non-antiviral actions exerted by interferons, we cloned a full-length cDNA copy of the 1.8-1.9 X 10(3)-base 56-kDa-protein mRNA and determined its sequence. The cDNA contains 1662 nucleotides derived from the 56-kDa-protein mRNA, including a poly(A) tail of 20 residues. Primer extension experiments indicate that the 5' end of this cDNA clone is probably located only 13 nucleotides downstream of the actual cap site of the 56-kDa-protein mRNA. It consists of a 64-nucleotide-long 5'-non-coding segment, a coding segment of 1434 nucleotides terminated by a TAG triplet and a 141-nucleotide 3'-non-coding segment. The encoded protein of 478 amino acid residues has a molecular mass of 55335 Da and a single potential site for N-glycosylation. The protein contains an excess of basic amino acids and most of them are localized in the carboxy-terminal half of the molecule. A single [35S]methionine-labeled 56-kDa protein was obtained using an SP64 construction to allow the cell-free transcription and translation of the cloned cDNA. Microinjection of this labeled protein in Xenopus oocytes indicates that the 56-kDa protein is cytoplasmic.
当用干扰素处理人类细胞时，会诱导产生多种蛋白质，其中观察到一种分子量为56 kDa、功能未知的主要蛋白质。为了探索该蛋白质及其mRNA调控的分子基础，以便了解其生物学功能以及它对干扰素发挥的各种抗病毒和非抗病毒作用可能做出的贡献，我们克隆了1.8 - 1.9×10³个碱基的56 kDa蛋白质mRNA的全长cDNA拷贝并测定了其序列。该cDNA包含来自56 kDa蛋白质mRNA的1662个核苷酸，包括一个20个残基的聚腺苷酸尾。引物延伸实验表明，该cDNA克隆的5'端可能仅位于56 kDa蛋白质mRNA实际帽位点下游13个核苷酸处。它由一个64个核苷酸长的5'非编码区、一个由TAG三联体终止的1434个核苷酸的编码区和一个141个核苷酸的3'非编码区组成。编码的由478个氨基酸残基组成的蛋白质分子量为55335 Da，有一个潜在的N - 糖基化位点。该蛋白质含有过量的碱性氨基酸，且大多数位于分子的羧基末端一半。使用SP64构建体获得了单个[³⁵S]甲硫氨酸标记的56 kDa蛋白质，以实现克隆cDNA的无细胞转录和翻译。将这种标记的蛋白质显微注射到非洲爪蟾卵母细胞中表明，56 kDa蛋白质位于细胞质中。
