Kurzynska-Kokorniak Anna, Pokornowska Maria, Koralewska Natalia, Hoffmann Weronika, Bienkowska-Szewczyk Krystyna, Figlerowicz Marek
Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland.
Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, 80-822 Gdansk, Poland.
Sci Rep. 2016 Apr 5;6:23989. doi: 10.1038/srep23989.
The ribonuclease Dicer is a multidomain enzyme that plays a fundamental role in the biogenesis of small regulatory RNAs (srRNAs), which control gene expression by targeting complementary transcripts and inducing their cleavage or repressing their translation. Recent studies of Dicer's domains have permitted to propose their roles in srRNA biogenesis. For all of Dicer's domains except one, called DUF283 (domain of unknown function), their involvement in RNA substrate recognition, binding or cleavage has been postulated. For DUF283, the interaction with Dicer's protein partners has been the only function suggested thus far. In this report, we demonstrate that the isolated DUF283 domain from human Dicer is capable of binding single-stranded nucleic acids in vitro. We also show that DUF283 can act as a nucleic acid annealer that accelerates base-pairing between complementary RNA/DNA molecules in vitro. We further demonstrate an annealing activity of full length human Dicer. The overall results suggest that Dicer, presumably through its DUF283 domain, might facilitate hybridization between short RNAs and their targets. The presented findings reveal the complex nature of Dicer, whose functions may extend beyond the biogenesis of srRNAs.
核糖核酸酶Dicer是一种多结构域酶，在小调控RNA（srRNA）的生物合成中发挥着重要作用，srRNA通过靶向互补转录本并诱导其切割或抑制其翻译来控制基因表达。最近对Dicer结构域的研究使得人们能够提出它们在srRNA生物合成中的作用。除了一个名为DUF283（功能未知结构域）的结构域外，对于Dicer的所有结构域，都假定它们参与RNA底物的识别、结合或切割。对于DUF283，与Dicer的蛋白质伙伴的相互作用是迄今为止唯一被提出的功能。在本报告中，我们证明从人Dicer中分离出的DUF283结构域在体外能够结合单链核酸。我们还表明DUF283可以作为一种核酸退火剂，在体外加速互补RNA/DNA分子之间的碱基配对。我们进一步证明了全长人Dicer的退火活性。总体结果表明，Dicer可能通过其DUF283结构域促进短RNA与其靶标之间的杂交。所呈现的研究结果揭示了Dicer的复杂性质，其功能可能超出srRNA的生物合成。
