Leebonoi Wantana, Sukthaworn Suchitraporn, Panyim Sakol, Udomkit Apinunt
Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhon Pathom, 73170, Thailand.
Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhon Pathom, 73170, Thailand; Department of Biochemistry, Faculty of Sciences, Mahidol University, Rama VI Road, Phayathai, Bangkok, 10400, Thailand.
Fish Shellfish Immunol. 2015 Feb;42(2):280-8. doi: 10.1016/j.fsi.2014.11.014. Epub 2014 Nov 20.
Argonaute is a key protein of the small-RNA guided gene regulation process. The Argonaute family is generally divided into two subfamilies; AGO and PIWI. In this study, a cDNA encoding a novel type of Argonaute (PmAgo4) in the black tiger shrimp Penaeus monodon was identified and characterized. PmAgo4 cDNA contained an open reading frame of 2433 nucleotides that can be translated into a deduced amino acid with the conserved PAZ and PIWI domains. PmAgo4 was phylogenetically clustered with the AGO subfamily while exhibited a gonad-specific expression pattern similar to that of proteins in the PIWI subfamily. The expression of PmAgo4 did not change significantly in response to either double-stranded RNA or yellow head virus injection suggesting that PmAgo4 may not be the main AGO proteins that play a role in dsRNA-mediated gene silencing or antiviral defense. Interestingly, PmAgo4 appeared to participate in the control of transposons since the activation of both DNA transposon and retrotransposon was detected in the testis of PmAgo4-knockdown shrimp. Our study thus provided the first evidence for an unusual type of the AGO proteins that was predominantly expressed in shrimp gonad and implication of its role in protecting the shrimp genome against an invasion of transposons.
Argonaute是小RNA引导的基因调控过程中的关键蛋白。Argonaute家族通常分为两个亚家族：AGO和PIWI。在本研究中，鉴定并表征了一种编码黑虎虾凡纳滨对虾新型Argonaute（PmAgo4）的cDNA。PmAgo4 cDNA包含一个2433个核苷酸的开放阅读框，可翻译成具有保守PAZ和PIWI结构域的推导氨基酸。PmAgo4在系统发育上与AGO亚家族聚类，同时表现出与PIWI亚家族蛋白质相似的性腺特异性表达模式。PmAgo4的表达在双链RNA或黄头病毒注射后没有显著变化，这表明PmAgo4可能不是在dsRNA介导的基因沉默或抗病毒防御中起作用的主要AGO蛋白。有趣的是，PmAgo4似乎参与了转座子的控制，因为在PmAgo4敲低虾的睾丸中检测到了DNA转座子和逆转录转座子的激活。因此，我们的研究首次提供了一种不寻常类型的AGO蛋白的证据，该蛋白主要在虾性腺中表达，并暗示了其在保护虾基因组免受转座子入侵方面的作用。
