Huang Y, Carmichael G G
Department of Microbiology, University of Connecticut Health Center, Farmington, CT 06030, USA.
Proc Natl Acad Sci U S A. 1997 Sep 16;94(19):10104-9. doi: 10.1073/pnas.94.19.10104.
Histone mRNAs are naturally intronless and accumulate efficiently in the cytoplasm. To learn whether there are cis-acting sequences within histone genes that allow efficient cytoplasmic accumulation of RNAs, we made recombinant constructs in which sequences from the mouse H2a gene were cloned into a human beta-globin cDNA. By using transient transfection and RNase protection analysis, we demonstrate here that a 100-bp sequence within the H2a coding region permits efficient cytoplasmic accumulation of the globin cDNA transcripts. We also show that this sequence appears to suppress splicing and can functionally replace Rev and the Rev-responsive element in the cytoplasmic accumulation of unspliced HIV-1-related mRNAs. Like the Rev-responsive element, this sequence acts in an orientation-dependent manner. We thus propose that the sequence identified here may be a member of the cis-acting elements that facilitate the cytoplasmic accumulation of naturally intronless gene transcripts.
组蛋白mRNA天然无内含子，并在细胞质中高效积累。为了了解组蛋白基因内是否存在允许RNA在细胞质中高效积累的顺式作用序列，我们构建了重组体，其中将小鼠H2a基因的序列克隆到了人β-珠蛋白cDNA中。通过瞬时转染和RNA酶保护分析，我们在此证明H2a编码区内的一段100个碱基对的序列可使珠蛋白cDNA转录本在细胞质中高效积累。我们还表明，该序列似乎能抑制剪接，并且在未剪接的HIV-1相关mRNA的细胞质积累过程中，在功能上可替代Rev和Rev反应元件。与Rev反应元件一样，该序列以方向依赖的方式起作用。因此，我们提出这里鉴定出的序列可能是促进天然无内含子基因转录本在细胞质中积累的顺式作用元件的成员。
