Sequencing of Argonaute-bound microRNA/mRNA hybrids reveals regulation of the unfolded protein response by microRNA-320a

• DOI: 10.1371/journal.pgen.1009934
• Publication Date: 2021-12-16T18:27:48Z
• Authors: Christopher J. Fi...; Lu Li; Nicholas M. Hiers; Tianqi Li; Peike Sheng; Taha Huda; Jixiu Shan; Lauren Gay; Tongjun Gu; Jiang Bian; Michael S. Kilberg; Rolf Renne; Mingyi Xie
• Keywords: Drosha; Dicer; Argonaute; Calnexin

MicroRNAs (miRNA) are short non-coding RNAs widely implicated in gene regulation. Most metazoan miRNAs utilize the RNase III enzymes Drosha and Dicer for biogenesis. One notable exception is RNA polymerase II transcription start sites (TSS) whose biogenesis does not require Drosha. The functional importance of TSS-miRNA uncertain. To better understand function TSS-miRNAs, we applied a modified C rosslinking, L igation, nd S equencing H ybrids on Argonaute (AGO-qCLASH) to identify targets TSS-miRNAs HCT116 colorectal cancer cells with or without DROSHA knockout. We observed that miR-320a hybrids dominate identified by AGO-qCLASH. Targets enriched eIF2 signaling pathway, downstream component unfolded protein response. Consistently, mimic- antagomir- transfected cells, differentially expressed products associated signaling. Within AGO-qCLASH data, endoplasmic reticulum (ER) chaperone calnexin as direct down-regulated target, thus connecting During ER stress, but amino acid deprivation, up-regulates ATF4, critical factor resolving stress. In summary, our study investigates targetome establishes regulator