Multicomponent complex of RNA and proteins that is composed of four active spliceosomes, termed native spliceosomes, connected to each other by the pre-mRNA. The supraspliceosome is the nuclear machine where the pre-mRNA processing takes place, like the 5'-end capping, 3'-end cleavage, splicing and editing. [ GOC:ans http://www.ncbi.nlm.nih.gov/pubmed/19282290 GOC:jl ]