Dobner P R, Kislauskis E, Wentworth B M, Villa-Komaroff L
Nucleic Acids Res. 1987 Jan 12;15(1):199-218. doi: 10.1093/nar/15.1.199.
The primary structures of two overlapping novel alpha-tubulin cDNA clones isolated from a Macaca fascicularis testis cDNA library and the corresponding human gene are presented. Although the general structure of the human gene conforms to that of previously described mammalian alpha-tubulin genes, there is a surprising difference: the ATG initiator codon is conspicuously absent. The macaque testis cDNA similarly lacks the initiator methionine, but otherwise encodes a variant alpha-tubulin isotype precisely conserved in the human gene. RNA blot analysis in the macaque, using a 3' untranslated region probe, revealed the existence of two additional related transcripts expressed in every tissue examined except the adult testis. Sequence comparisons indicate that the 2.0 kb testis transcript and one of the additional transcripts result from differential transcription of the same gene. The two transcripts differ only at the 5' end as a result of the recruitment of different 5' exons. Curiously, the 5' exon utilized outside the testis encodes an initiator methionine in the expected location.
本文展示了从食蟹猴睾丸cDNA文库中分离得到的两个重叠的新型α-微管蛋白cDNA克隆的一级结构以及相应的人类基因。尽管人类基因的总体结构与先前描述的哺乳动物α-微管蛋白基因一致，但存在一个惊人的差异：明显缺少ATG起始密码子。猕猴睾丸cDNA同样缺少起始甲硫氨酸，但在其他方面编码一种在人类基因中精确保守的α-微管蛋白异构体。使用3'非翻译区探针在猕猴中进行的RNA印迹分析表明，除成年睾丸外，在每个检测组织中都存在另外两种相关转录本。序列比较表明，2.0 kb的睾丸转录本和其中一种额外的转录本是同一基因差异转录的结果。由于招募了不同的5'外显子，这两种转录本仅在5'端有所不同。奇怪的是，在睾丸外使用的5'外显子在预期位置编码起始甲硫氨酸。
