Schäfer M, Kuhn R, Bosse F, Schäfer U
Institut für Genetik, Heinrich-Heine-Universität Düsseldorf, Germany.
EMBO J. 1990 Dec;9(13):4519-25. doi: 10.1002/j.1460-2075.1990.tb07903.x.
We have previously shown that Mst87F (previously called mst(3)g1-9), a gene which is exclusively expressed in the male germ line of Drosophila melanogaster, is subject to negative translational control. While transcription of this gene takes place premeiotically, translation occurs only after the elongation of spermatids is complete. We report here the identification of a sequence element within the first 45 nucleotides of the leader which is crucial for this translational regulation. Sequence comparison with six other genes, which form a gene family with Mst87F, shows the conservation of a twelve nucleotide element within this leader segment. It is found in all genes at positions +28 to +39 of the leader. Deletion of this element or alteration of two nucleotides by in vitro mutagenesis both lead to the breakdown of the translational control mechanism. The poly(A) tail of the Mst87F mRNA becomes longer and heterogeneous in length when the mRNA is recruited for translation. We present evidence that the control for this additional polyadenylation also resides within the conserved element of the leader.
我们之前已经表明，Mst87F（之前称为mst(3)g1-9）是一种仅在黑腹果蝇雄性生殖系中表达的基因，它受到负向翻译控制。虽然该基因的转录发生在减数分裂前期，但翻译仅在精子细胞伸长完成后才会发生。我们在此报告，在该基因前导序列的前45个核苷酸内鉴定出一个对这种翻译调控至关重要的序列元件。与其他六个与Mst87F形成基因家族的基因进行序列比较，结果显示在该前导序列片段内有一个12个核苷酸的元件保守存在。在所有基因的前导序列+28至+39位置都能找到它。通过体外诱变删除该元件或改变两个核苷酸，都会导致翻译控制机制失效。当Mst87F mRNA被募集进行翻译时，其多聚腺苷酸尾巴会变长且长度变得不均一。我们提供的证据表明，这种额外的多聚腺苷酸化的控制也存在于前导序列保守元件内。
