Buzdin Anton, Gogvadze Elena, Lebrun Marc-Henri
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117871, Russia.
FEBS Lett. 2007 Jun 26;581(16):2877-82. doi: 10.1016/j.febslet.2007.05.034. Epub 2007 May 25.
Chimeric retrogenes, found in mammalian and fungal genomes, are bipartite elements composed of DNA copies of cellular transcripts either directly fused to each other or fused to the 3' part of a LINE retrotransposon. These cellular transcripts correspond to messenger RNAs, ribosomal RNAs, small nuclear RNAs and 7SL RNA. The chimeras are likely formed by RNA template switches during reverse transcription of LINE elements by their retrotranspositional machinery. The 5' part of chimeras are copies of nucleolar RNAs, suggesting that the nucleolus plays a significant role in LINE retrotransposition. RNAs from the nucleolus might have protective function against retroelement invasion or, alternatively, the nucleolus may be required for retrotranspositional complex assembly and maturation. These hypotheses will be discussed in this review.
嵌合逆转录基因存在于哺乳动物和真菌基因组中，是由细胞转录本的DNA拷贝组成的二分元件，这些转录本要么彼此直接融合，要么与LINE逆转录转座子的3'部分融合。这些细胞转录本对应于信使RNA、核糖体RNA、小核RNA和7SL RNA。这些嵌合体可能是在LINE元件通过其逆转录转座机制进行逆转录过程中由RNA模板转换形成的。嵌合体的5'部分是核仁RNA的拷贝，这表明核仁在LINE逆转录转座中起重要作用。来自核仁的RNA可能具有抵御逆转录元件入侵的保护功能，或者，核仁可能是逆转录转座复合体组装和成熟所必需的。本综述将讨论这些假说。
