Solid-phase synthesis of branched oligoribonucleotides related to messenger RNA splicing intermediates

Abstract
The chemical synthesis of oligoribonucleotides containing vicinal (2′-5′)- and (3′-5′)- phosphodiester linkages is described. The soiid-phase method, based on silyl-phosphoramidite chemistry, was applied to the synthesis of a seiles of branched RNA [(Xp)nA2′ (pN)n3′(pN)n] reiated to the splicing intermediates derived from Saccharomyces cerevisiae rp51a premessenger RNA. The branched oligonucleotides have been thoroughiy characterized by nucleoside and branched nucleotide composition analysis. Branched oligoribonucieotides will be useful in the study of messenger RNA splicing and in determining the biological role of RNA ‘lariats’ and ‘forks’ in vivo.