Bösl M R, Seldin M F, Nishimura S, Taketo M
Banyu Tsukuba Research Institute, Merck, Japan.
Mol Gen Genet. 1995 Aug 21;248(3):247-52. doi: 10.1007/BF02191590.
The tRNA([Ser]Sec) molecule mediates the synthesis of selenoproteins by incorporating selenocysteine into specific UGA codons upon translation of mRNAs that encode selenocysteine-containing proteins. The mouse gene encoding tRNA([Ser]Sec) (Trsp) was isolated from a genomic library and sequenced. The mouse sequence is colinear with its tRNA product, and contains a C to T transition relative to the homologous genes in other vertebrates except rat. Transcriptional control motifs found 5' to the tRNA coding region included a TATA element, a PSE element and an SPH motif which is associated with an octamer motif. A Northern hybridization analysis showed highest expression in the testis, followed by thymus, spleen, kidney, ovary, brain, liver, heart and skeletal muscle. Surprisingly, the expression level was lowest in embryonic stem cells. These results suggest a tissue-specific transcriptional control. Using restriction fragment length variants (RFLVs) in interspecific backcross mice between Mus musculus (C3H strain) and Mus spretus, the Trsp gene was mapped to the proximal region of mouse Chr 7, cosegregating with octamer-binding transcription factor-2 (Otf2).
tRNA（[Ser]Sec）分子通过在编码含硒代半胱氨酸蛋白质的mRNA翻译过程中将硒代半胱氨酸掺入特定的UGA密码子来介导硒蛋白的合成。从小鼠基因组文库中分离并测序了编码tRNA（[Ser]Sec）（Trsp）的基因。小鼠序列与其tRNA产物共线性，并且相对于除大鼠以外的其他脊椎动物中的同源基因含有一个从C到T的转变。在tRNA编码区5'端发现的转录控制基序包括一个TATA元件、一个PSE元件和一个与八聚体基序相关的SPH基序。Northern杂交分析表明，在睾丸中表达最高，其次是胸腺、脾脏、肾脏、卵巢、大脑、肝脏、心脏和骨骼肌。令人惊讶的是，在胚胎干细胞中的表达水平最低。这些结果表明存在组织特异性转录调控。利用小家鼠（C3H品系）和西班牙小鼠种间回交小鼠中的限制性片段长度变异（RFLV），将Trsp基因定位到小鼠第7号染色体的近端区域，与八聚体结合转录因子-2（Otf2）共分离。
