Hernández G, Diez del Corral R, Santoyo J, Campuzano S, Sierra J M
Centro de Biologia Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, Spain.
Mol Gen Genet. 1997 Feb 20;253(5):624-33. doi: 10.1007/s004380050365.
Drosophila melanogaster contains a single copy of the gene encoding translation eukaryotic initiation factor eIF-4E, which maps in the 67A2B1 region of chromosome 3L. A genomic clone containing the entire eIF-4E gene was isolated and sequenced. Comparison of this sequence with a cDNA previously obtained in our laboratory and 5'-RACE analysis revealed the existence of three mRNAs that are generated by alternative splicing of a primary transcript. All of them have different 5' untranslated leader regions. Two of the mRNAs encode the same eIF-4E polypeptide, whose sequence has been deduced from the cDNA clone. The third mRNA species contains a new open reading frame, possibly encoding another isoform of eIF-4E, which is very similar in size to the other but has a different N-terminal sequence. Several sequences which may be involved in the regulation of transcription initiation of the eIF-4E gene, except for a consensus TATA box, were found upstream of the putative transcription initiation sites. Expression of the eIF-4E gene is spatially and temporally controlled during embryonic development. It is ubiquitously expressed during embryogenesis but transcripts preferentially accumulate in certain tissues, particularly in the pole cells, at different developmental stages.
黑腹果蝇含有编码真核生物翻译起始因子eIF - 4E的基因的单拷贝，该基因定位于3L染色体的67A2B1区域。分离并测序了一个包含整个eIF - 4E基因的基因组克隆。将该序列与我们实验室先前获得的cDNA进行比较以及5'-RACE分析表明，存在由初级转录本的可变剪接产生的三种mRNA。它们都具有不同的5'非翻译前导区。其中两种mRNA编码相同的eIF - 4E多肽，其序列已从cDNA克隆推导得出。第三种mRNA含有一个新的开放阅读框，可能编码eIF - 4E的另一种同工型，其大小与另一种非常相似，但N端序列不同。在假定的转录起始位点上游发现了几个可能参与eIF - 4E基因转录起始调控的序列，除了一个共有TATA框。eIF - 4E基因的表达在胚胎发育过程中受到空间和时间的控制。它在胚胎发生过程中普遍表达，但转录本在不同发育阶段优先在某些组织中积累——特别是在极细胞中。
