Martinez-Gonzalez J, Hegardt F G
Unit of Biochemistry, School of Pharmacy, University of Barcelona, Spain.
Eur J Biochem. 1995 Nov 15;234(1):284-92. doi: 10.1111/j.1432-1033.1995.284_c.x.
Cyclophilins are an abundant and ubiquitous class of proteins first identified by their high affinity for the immunosuppressive drug cyclosporin A. Cyclophilins have peptidylprolyl cis/trans-isomerase activity in vitro, and thus may be involved in protein folding and trafficking in vivo. In this study, we report the cloning and characterization of a Blattella germanica cyclophilin cDNA. Analysis of this 846-bp cDNA reveals an open reading frame coding for a polypeptide of 164 amino acid residues with a molecular mass of 17934 Da. This B. germanica cyclophilin shares a central peptidylprolyl cis/trans-isomerase and a cyclosporin-A-binding domain with other cyclophilin sequences. The B. germanica cyclophilin amino acid sequence shares 83% identity with the cytosolic cyclophilin isoform from Drosophila melanogaster (Cyp-1). This identity suggests that B. germanica cyclophilin is a member of the cytosolic cyclophilin A (CyPA) family. From the alignment of cyclophilin sequences, we have found that 62 residues (positional identity of 40%) have remained invariant in eukaryotes for more than 1 billion years of divergence. We calculated a unit evolutionary period of 30.9 million years for the cytosolic isoform. Northern-blot analyses show that B. germanica CyPA mRNA is abundant, and present in all insect organs tested. The highest values for B. germanica cyclophilin mRNA tissue content were found in 6-day-old ovary, followed by brain, testis, and gut (15-30% the content of ovary). The muscle, fat body, and colleterial gland contained the lowest cyclophilin mRNA level (1-5% the content of ovary). There is a developmental pattern of gene expression affecting the embryo stages. These results suggest that this ubiquitously expressed B. germanica cyclophilin is subject to a differential regulation in tissues and during development. Southern-blot analysis of B. germanica DNA shows that only one copy of the CyPA gene is present per genome, whereas at least 20 genes or pseudogenes were detected in the mammalian genome.
亲环蛋白是一类丰富且广泛存在的蛋白质，最初因其对免疫抑制药物环孢菌素A具有高亲和力而被鉴定出来。亲环蛋白在体外具有肽基脯氨酰顺/反异构酶活性，因此可能参与体内蛋白质的折叠和运输。在本研究中，我们报告了德国小蠊亲环蛋白cDNA的克隆和特征分析。对这个846个碱基对的cDNA进行分析，发现一个开放阅读框，编码一个由164个氨基酸残基组成的多肽，分子量为17934道尔顿。这种德国小蠊亲环蛋白与其他亲环蛋白序列共享一个中央肽基脯氨酰顺/反异构酶和一个环孢菌素A结合结构域。德国小蠊亲环蛋白的氨基酸序列与黑腹果蝇的胞质亲环蛋白异构体（Cyp-1）具有83%的同一性。这种同一性表明德国小蠊亲环蛋白是胞质亲环蛋白A（CyPA）家族的成员。通过亲环蛋白序列的比对，我们发现62个残基（位置同一性为40%）在超过10亿年的真核生物分化过程中保持不变。我们计算出胞质异构体的单位进化周期为3090万年。Northern杂交分析表明，德国小蠊CyPA mRNA含量丰富，且在所测试的所有昆虫器官中均有表达。德国小蠊亲环蛋白mRNA组织含量最高的值出现在6日龄卵巢中，其次是脑、睾丸和肠道（为卵巢含量的15 - 30%）。肌肉、脂肪体和粘液腺中亲环蛋白mRNA水平最低（为卵巢含量的1 - 5%）。存在影响胚胎阶段的基因表达发育模式。这些结果表明，这种广泛表达的德国小蠊亲环蛋白在组织和发育过程中受到差异调节。对德国小蠊DNA的Southern杂交分析表明，每个基因组中仅存在一个CyPA基因拷贝，而在哺乳动物基因组中检测到至少20个基因或假基因。
