New Roles for the Snp1 and Exo84 Proteins in Yeast Pre-mRNA Splicing

摘要: The mammalian 70K protein, a component of the U1 small nuclear ribonucleoprotein involved in pre-mRNA splicing, interacts with number proteins important for regulating constitutive and alternative splicing. Similar that interact yeast homolog Snp1p, have yet to be identified. We used two-hybrid system find four U1-Snp1 associating (Usa) proteins. Two these physically associate Snp1p as assayed by coimmunoprecipitation. One is Prp8p, known, essential spliceosomal component. This interaction suggests some novel functions late spliceosome development. other, Exo84p, conserved subunit exocyst, an eight-protein complex functioning secretion. show here Exo84p also A temperature-sensitive exo84 mutation caused increased ratios mRNA Rpl30 actin transcripts cells incubated at non-permissive temperature. led defect splicing prespliceosome formation vitro; indication has direct role results elucidate surprising link between