Drosophila Gemin5 binds to UsnRNA and another specific group of ncRNAs

Pre-messenger RNA (pre-mRNA) splicing is an indispensable step in protein synthesis. Human RNA splicing is mediated by spliceosome, the molecular machinery that is comprised of various U small nuclear ribonucleoproteins (UsnRNPs). The UsnRNPs biogenesis is highly regulated by a protein complex called the Survival of Motor Neuron complex (SMN complex). The SMN complex is composed of the SMN protein, sm proteins and Gemin2-8. Gemin5 has been identified as the UsnRNA-binding protein in SMN complex. Rigor mortis (Rig) is the homolog of human Gemin5 in Drosophila. It is found highly expressed in the central nervous system of larvae and the ovaries of adult flies. We showed that Rig share the function of human Gemin5 in binding UsnRNA with high affinity and specificity. By means of RNA immunoprecipitation and next-generation sequencing, we further reveal that Rig binds to another group of non-coding RNAs, suggesting that Rig is involved in other pathways of RNA binding or biogenesis.