Regulation of Microprocessor assembly and localization via Pasha’s WW domain in C. elegans

Primary microRNA (pri-miRNA) transcripts are processed by a protein complex called the Microprocessor comprised of the ribonuclease Drosha and its RNA binding partner DGCR8/Pasha. We sequenced small RNAs from animals containing a mutation in the WW domain of C. elegans pash-1. We found that these mutants have a modest but widespread reduction in miRNA levels when grown at 20˚C, which is further enhanced when grown at 25˚C. The results demonstrate a requirement for the WW domain in processing miRNAs in C. elegans. Small RNA high-throughput sequencing was done using RNA isolated from wild type and pash-1(ram33)mutant whole gravid adult C. elegans grown at 20˚C or 25˚C. The tinyRNA pipeline was used to quantitatively assess miRNA levels.