C. elegans PPM-2 regulates small RNA function by stabilizing Argonaute proteins

Argonaute proteins associate with small non-coding RNAs such as microRNAs, piRNAs and siRNAs to regulate gene expression required for cell proliferation and differentiation. Thse Argonaute proteins are the major components of effector complexes of non-coding RNA pathways. In C. elegans, we identified PPM-2, a Mg2+/Mn2+-dependent serine/threonine phosphatase, as a new regulator of the small RNA pathways in C. elegans. We demonstrate that PPM-2 is involved in the regulation of the let-7 microRNA family but also in the regulation of nuclear RNAi as well as it contributes to the expression of piRNAs. The loss of ppm-2 affects the expression level of Type 1 piRNAs and the stability of ALG-1, PRG-1 and NRDE-3 Argonaute proteins by sending them to the proteasomal degradation pathway. Altogether, our findings suggest that PPM-2 is regulating the function of small non-coding RNA pathways by preventing Argonaute proteins to be degraded via the proteasomal pathway. Develop a novel protocol to clone small RNA and mRNA