SRA

In eukaryotes, ribosomal RNA biogenesis consists of ribosomal DNA transcription to pre-rRNA, which must be modified and processed in the nucleus resulting in the 18S, 5.8S, and 28S ribosomal units. Molecular components involved in this process comprise the catalytic ribonucleoproteins complexes (snoRNPs) formed by non-coding RNAs classified as box C/D and box H/ACA snoRNA that associates to at least four proteins highly conserved through evolution and combined to multiple transient proteins. Taking advantage of computational and multidisciplinary experimental approaches, we determine that the orphan EhARPv2, a member of the Actin-related family from Entamoeba histolytica, interacts with nucleolar proteins. EhARPv2 and its partners here identified colocalize in the nuclear periphery, considered the nucleolus, and interact with both box C/D and H/ACA snoRNAs. Moreover, we find the reassortment of some components of snoRNPs from C/D- or H/ACA complexes mixed in vitro and in entire cells indicating that in E. histolytica snoRNP of C/D or H/ACA machineries alternate using common elements and that EhARPv2 is a part of this peculiar snoRNP. Our findings substantiate a role for EhARPv2 in the biogenesis of ribosomal RNA. Overall design: CLIP-seq assay with a-EhARPv2, a-EhNop58, a-EhABP-12035 and a-EhFibrillarin in Entamoeba histolytica HM1: IMSS.