Functional Study of the Retrotransposon-Derived Human PEG10 Protease
Functional Study of the Retrotransposon-Derived Human PEG10 Protease
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DOI：
10.3390/ijms21072424
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发表时间：
2020-04-01
影响因子：
5.6
通讯作者：
Tozser, Jozsef
中科院分区：
文献类型：
--
作者：
Golda, Maria;Motyan, Janos Andras;Tozser, Jozsef
父系表达基因10 （PEG10）是人类反转录转座子衍生的印迹基因。PEG10的mRNA编码两种蛋白亚型：gag -样蛋白（RF1(PEG10)）通过阅读框1编码，gag - pol -样多蛋白（RF1/RF2(PEG10)）通过阅读框1和2编码。这些蛋白质通过典型的逆转录病毒移码机制进行翻译。RF2（PEG10）的蛋白酶（PR）结构域包含一个- asp - ser - gly -序列，这与逆转录病毒天冬氨酸蛋白酶的- asp - ser /Thr-Gly-活性位点基序相对应。RF2的天冬氨酸蛋白酶结构域（PEG10）的功能尚不清楚。为了阐明PEG10蛋白酶（PRPEG10）的功能，我们设计了一个移码突变体((fs)RF1/RF2(PEG10))，并与RF1/RF2（PEG10）形式进行比较。为了研究PRPEG10对细胞增殖和活力的影响，我们用编码RF1/RF2（PEG10）、移码突变体(（fs)RF1/RF2(PEG10)）或PR活性位点（D370A）突变体（fs）RF1/RF2（PEG10）的质粒转染了哺乳动物HEK293T和HaCaT细胞。我们的研究结果表明，（fs）RF1/RF2（PEG10）过表达导致细胞增殖增加。值得注意的是，转染（fs）RF1/RF2（PEG10）对细胞活力有不利影响。我们假设PRPEG10在这种逆转录病毒残体的功能中发挥重要作用，介导细胞增殖并可能参与抑制细胞凋亡。
Paternally expressed gene 10 (PEG10) is a human retrotransposon-derived imprinted gene. The mRNA of PEG10 encodes two protein isoforms: the Gag-like protein (RF1(PEG10)) is coded by reading frame 1, while the Gag-Pol-like polyprotein (RF1/RF2(PEG10)) is coded by reading frames 1 and 2. The proteins are translated by a typical retroviral frameshift mechanism. The protease (PR) domain of RF2(PEG10) contains an -Asp-Ser-Gly- sequence, which corresponds to the consensus -Asp-Ser/Thr-Gly- active-site motif of retroviral aspartic proteases. The function of the aspartic protease domain of RF2(PEG10) remains unclear. To elucidate the function of PEG10 protease (PRPEG10), we designed a frameshift mutant ((fs)RF1/RF2(PEG10)) for comparison with the RF1/RF2(PEG10) form. To study the effects of PRPEG10 on cellular proliferation and viability, mammalian HEK293T and HaCaT cells were transfected with plasmids coding for either RF1/RF2(PEG10), the frameshift mutant ((fs)RF1/RF2(PEG10)), or a PR active-site (D370A) mutant (fs)RF1/RF2(PEG10). Our results indicate that (fs)RF1/RF2(PEG10) overexpression results in increased cellular proliferation. Remarkably, transfection with (fs)RF1/RF2(PEG10) had a detrimental effect on cell viability. We hypothesize that PRPEG10 plays an important role in the function of this retroviral remnant, mediating the proliferation of cells and possibly implicating it in the inhibition of apoptosis.