Zhouravleva G, Schepachev V, Petrova A, Tarasov O, Inge-Vechtomov S
Department of Genetics, St Petersburg State University, St Petersburg, Russia.
IUBMB Life. 2006 Apr;58(4):199-202. doi: 10.1080/15216540600686862.
Two release factors (eRF1 and eRF3) are responsible for correct termination of translation in eukaryotes. While the structure and functions of different domains of eRF1 have been sufficiently characterized, the role of eRF3 in translation termination remains unclear. Moreover, the N-terminal domain of eRF3, which is dispensable for termination, is highly divergent. Mammalian eRF3 exists in two isotypes, eRF3a and eRF3b, encoded by genes GSPT1 and GSPT2, respectively. Here we propose that GSPT2 originated through retrotransposition of processed GSPT1 transcript into the genome. Comparison of the 5' non-coding sequences of both genes revealed existence of potential promoter element in 5'UTR of GSPT1 which we suppose to be responsible for GSPT2 transcription.
两种释放因子（eRF1和eRF3）负责真核生物中翻译的正确终止。虽然eRF1不同结构域的结构和功能已得到充分表征，但eRF3在翻译终止中的作用仍不清楚。此外，eRF3的N端结构域对终止是可有可无的，且高度分化。哺乳动物的eRF3存在两种同种型，即eRF3a和eRF3b，分别由基因GSPT1和GSPT2编码。在此我们提出，GSPT2起源于加工后的GSPT1转录本逆转座到基因组中。对这两个基因5'非编码序列的比较揭示，GSPT1的5'UTR中存在潜在的启动子元件，我们认为该元件负责GSPT2的转录。
