Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, Japan.
Mol Cell Biol. 2012 Jan;32(2):458-69. doi: 10.1128/MCB.06162-11. Epub 2011 Nov 21.
Long interspersed elements (LINEs) are mobile elements that comprise a large proportion of many eukaryotic genomes. Although some LINE-encoded open reading frame 1 proteins (ORF1ps) were suggested to be required for LINE mobilization through binding to their RNA, their general role is not known. The ZfL2-1 ORF1p, which belongs to the esterase-type ORF1p, is especially interesting because it has no known RNA-binding domain. Here we demonstrate that ZfL2-1 ORF1p has all the canonical activities associated with known ORF1ps, including self-interaction, nucleic acid binding, and nucleic acid chaperone activities. In particular, we showed that its chaperone activity is reversible, suggesting that the chaperone activities of many other ORF1ps are also reversible. From this discovery, we propose that LINE ORF1ps play a general role in LINE integration by forming a complex with LINE RNA and rearranging its conformation.
长散在核元件（LINEs）是一类可移动元件，它们构成了许多真核生物基因组的很大一部分。虽然一些 LINE 编码的开放阅读框 1 蛋白（ORF1ps）被认为通过与它们的 RNA 结合而被需要用于 LINE 移动，但其一般作用尚不清楚。ZfL2-1 ORF1p 属于酯酶型 ORF1p，特别有趣，因为它没有已知的 RNA 结合结构域。在这里，我们证明 ZfL2-1 ORF1p 具有与已知的 ORF1ps 相关的所有典型活性，包括自我相互作用、核酸结合和核酸伴侣活性。特别是，我们表明其伴侣活性是可逆的，这表明许多其他 ORF1ps 的伴侣活性也是可逆的。从这一发现中，我们提出 LINE ORF1ps 通过与 LINE RNA 形成复合物并改变其构象，在 LINE 整合中发挥一般作用。
