Nucleotide sequence analysis of the chicken c-myc gene reveals homologous and unique coding regions by comparison with the transforming gene of avian myelocytomatosis virus MC29, delta gag-myc.
Nucleotide sequence analysis of the chicken c-myc gene reveals homologous and unique coding regions by comparison with the transforming gene of avian myelocytomatosis virus MC29, delta gag-myc.
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通过与禽骨髓细胞瘤病毒 MC29 的转化基因 delta gag-myc 比较，鸡 c-myc 基因的核苷酸序列分析揭示了同源且独特的编码区。
DOI：
10.1073/pnas.80.8.2146
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发表时间：
1983
影响因子：
11.1
通讯作者：
Papas,TS
中科院分区：
文献类型：
--
作者：
Watson,DK;Reddy,EP;Duesberg,PH;Papas,TS
骨髓细胞瘤病病毒MC29是一种带有混合转化基因(Delta gag-myc)的缺陷型禽反转录病毒，由逆转录病毒Gag基因的1,358个碱基对(BP)和1,568个碱基(v-myc)组成，称为c-myc。我们对克隆的c-myc基因进行了2,735个碱基的序列分析，其中包括1,568个碱基的v-myc相关区，971个碱基的插入序列，以及5‘端45个碱基和3’端195个碱基的独特侧翼序列。C-myc序列与已知的MC29序列的比对分析表明：(I)两个myc序列具有相同的阅读框，包括翻译终止信号；(Ii)c-myc和v-myc之间有9个核苷酸变化，对应于7个氨基酸变化；(Iii)c-myc的971个碱基的插入序列可由共识剪接信号定义为内含子；(Iv)c-myc独特的5‘端序列既可以将其阅读框延伸到与v-myc同源之外，也可以是内含子，因为它与该基因座的myc区连接是典型的3’剪接受体位点；(V)v-myc在其5‘端包含10个核苷酸，与本文分析的c-myc不共享，也不与已知的Gag基因共享，可能来自上游外显子；(6)c-myc基因座可产生终止信号位于v-myc和c-myc分歧点的83bp和119bp的mRNA。我们认为鸡c-myc基因与MC29株的onc基因具有同源的myc区，但在独特的5‘编码区存在差异，推测它们的蛋白产物可能具有不同的功能。MC29株的杂合onc基因可能是由c-myc基因通过删除5‘细胞编码序列，然后替换为病毒Gag基因的5’区而产生的。
Myelocytomatosis virus MC29 is a defective avian retrovirus with a hybrid transforming gene (delta gag-myc) consisting of a 1,358-base pair (bp) sequence from the retroviral gag gene and a 1,568-bp sequence (v-myc) shared with a cellular locus, termed c-myc. We have subjected to sequence analysis 2,735 bp of the cloned c-myc gene, which includes the v-myc-related region of 1,568 bp, an intervening sequence of 971 bp, and unique flanking sequences of 45 bp and 195 bp at the 5' and 3' ends, respectively. Analysis of the genetic information and alignment of the c-myc sequence with the known sequence of MC29 indicates that: (i) the two myc sequences share the same reading frame, including the translational termination signal; (ii) there are nine nucleotide changes between c-myc and v-myc that correspond to seven amino acid changes; (iii) the 971-bp intervening sequence of c-myc can be defined as an intron by consensus splice signals; (iv) the unique 5' sequence of c-myc could either extend its reading frame beyond the homology with v-myc or could be an intron because its junction with the myc region of the locus is a canonical 3' splice-acceptor site; (v) the v-myc contains 10 nucleotides at its 5' end not shared with the c-myc analyzed here and also not with known gag genes, probably derived from an upstream exon; and (vi) the c-myc locus can generate a mRNA whose termination signals have been identified to be located 83 bp and 119 bp from the point of divergence between the v-myc and c-myc. We conclude that the gene of the c-myc locus of the chicken and the onc gene of MC29 share homologous myc regions and differ in unique 5' coding regions and we speculate, on this basis, that their protein products may have different functions. The hybrid onc gene of MC29 must have been generated from the c-myc gene by deletion of the 5' cellular coding sequence, followed by substitution with the 5' region of the viral gag gene.