Molecular analysis of human and rat calmodulin complementary DNA clones. Evidence for additional active genes in these species.
Molecular analysis of human and rat calmodulin complementary DNA clones. Evidence for additional active genes in these species.
复制标题
人和大鼠钙调蛋白互补 DNA 克隆的分子分析。
DOI：
10.1016/s0021-9258(18)49306-4
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
S. Detera
中科院分区：
文献类型：
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作者：
B. Sengupta;F. Friedberg;S. Detera
从大鼠脑表达文库中分离到编码钙调蛋白的cDNA克隆lambda rCB1。测定了该序列并与先前描述的大鼠基因lambda SC4和lambda SC8的结构进行了比较（Nojima， H., and Sokabe， H. (1986) J. Mol. Biol. 190,391 -400）。在真实基因lambda rCB1和lambda SC4的编码区观察到忠实序列保守。两种cdna编码相同的氨基酸序列。然而，在这些克隆的3 ' -未翻译片段中发现了非常有限的序列同源性。令人惊讶的是，当lambda rCB1核苷酸结构与经过处理的无内含子基因lambda SC8进行比较时，在编码区和非编码区都发现了广泛的序列同源性。然而，lambda SC8和lambda rCB1的蛋白质序列是不同的。利用lambda rCB1片段筛选人胚胎细胞系表达文库，分离到一个钙调蛋白cDNA克隆lambda hCE1，并对其进行了鉴定。lambda hCE1序列与人类肝脏cDNA序列的比较(Wawrzynczak， E. J., and Perham， R. N. (1984) Biochem。第9卷（177-185页）揭示了实质性的结构性分歧。在5 ‘和3 ’非编码片段中，同源性明显较差，但编码区同源性为85%。lambda hCE1和hCWP编码的初级结构相同，与lambda rCB1和lambda SC4推导的蛋白序列相同。综上所述，这些结果表明，在人类和大鼠的基因组中，存在一个额外的活跃转录的钙调蛋白基因，以前没有发现过。在所有检测的组织中均观察到lambda rCB1和lambda hCE1的转录本，表明没有组织特异性表达。采用TaqI、HindIII和MspI检测钙调素基因多态性。
A cDNA clone, lambda rCB1, encoding calmodulin was isolated from a rat brain expression library. The sequence was determined and compared to the structures of the previously described rat genes, lambda SC4 and lambda SC8 (Nojima, H., and Sokabe, H. (1986) J. Mol. Biol. 190, 391-400). Faithful sequence conservation is observed in the coding regions of lambda rCB1 and lambda SC4, the bona fide gene. Both cDNAs encode identical amino acid sequence. Very limited sequence homology, however, is noted in the 3′-untranslated segments of these clones. Surprisingly, when the lambda rCB1 nucleotide structure is compared to the processed intronless gene, lambda SC8, extensive sequence homology is found both in the coding and noncoding regions. The inferred protein sequences of lambda SC8 and lambda rCB1, however, are divergent. Using a fragment of lambda rCB1 to screen an expression library derived from a human embryonic cell line, a calmodulin cDNA clone, lambda hCE1, was isolated and characterized. Comparison of the sequence of lambda hCE1 to the cDNA from human liver, hCWP (Wawrzynczak, E. J., and Perham, R. N. (1984) Biochem. Int. 9, 177-185), reveals substantial structural divergence. Strikingly poor homology is seen in the 5′- and 3′-noncoding segments, but the coding regions were 85% homologous. Both lambda hCE1 and hCWP encode proteins of identical primary structure which is equivalent to the protein sequence deduced from lambda rCB1 and lambda SC4. Taken together these results suggest the existence of an additional actively transcribed calmodulin gene, not previously identified, in each of the human and rat genomes. Transcripts of lambda rCB1 and lambda hCE1 were observed in all tissues examined indicating the absence of tissue-specific expression. Calmodulin gene polymorphisms were detected using TaqI, HindIII, and MspI.