Defining a new role of GW182 in maintaining miRNA stability

Abstract

GW182 binds to Argonaute (AGO) proteins and has a central role in miRNA-mediated gene silencing. Using lentiviral shRNAinduced GW182 knockdown in HEK293 cells, this study identifies a new role of GW182 in regulating miRNA stability. Stably knocking down GW182 or its paralogue TNRC6B reduces transfected miRNA-mimic half-lives. Replenishment of GW182 family proteins, as well as one of its domain D12, significantly restores the stability of transfected miRNA-mimic. GW182 knockdown reduces miRNA secretion via secretory exosomes. Targeted siRNA screening identifies a 3 0 -5 0 exoribonuclease complex responsible for the miRNA degradation only when GW182 is knocked down. Immunoprecipitation further confirms that the presence of GW182 in the RISC complex is critical in protecting Argonaute-bound miRNA.

MicroRNAs in spent blastocyst culture medium are derived from trophectoderm cells and can be explored for human embryo reproductive competence assessment

“…Indeed, a prominent feature of circulating miRNAs is their remarkable stability (51): they are protected by forming complexes with proteins such as Argonaute (52) and GW182 (53) or are encapsulated in exosomes that provide additional protection from degrading enzymes (54). Moreover, miRNAs are a specific product of the embryo that can be related to the quality of many differentiation processes that beset blastocyst differentiation and are not supposed to be already present in culture media.…”

Sources and Functions of Extracellular Small RNAs in Human Circulation

“…GW-bodies also contain GW182 and AGO2, proteins of the RISC complex which have also been identified in exosomes (69). Interestingly Yao et al reported that a knock-down of GW182 decreases the miRNA release via secretory exosomes (225). Furthermore, Guduric-Fuchs et al showed that a knock-out of AGO2 also reduces the incorporation of miRNAs into exosomes (72, 225).…”

“…Interestingly Yao et al reported that a knock-down of GW182 decreases the miRNA release via secretory exosomes (225). Furthermore, Guduric-Fuchs et al showed that a knock-out of AGO2 also reduces the incorporation of miRNAs into exosomes (72, 225). Whether this phenomenon is due to instability of the miRNAs, when unbound to AGO2 and/or GW182, or to the possibility that the miRNAs do not reach GW-bodies anymore, still needs to be elucidated.…”

Uptake and impact of natural diet-derived small RNA in invertebrates: Implications for ecology and agriculture

“…[105][106][107][108][109][110][111][112] miRNA sorting into exosomes can be influenced by a number of factors, 113 including dose, 114 3 0 end uridylation, 115 nucleotide sequence motifs, 116 interaction with RNA-binding proteins, 117,118 and localization to GW bodies. 119 Second, miRNAs can be incorporated into a variety of ribonucleoprotein complexes, including those containing ARGONAUTE family members, [120][121][122] HDL, 123,124 and HuR. 125 In addition, 2 other modes of sRNA spread that have been documented in vertebrates may play a role in invertebrates.…”