title: Human snRNP polypeptide D1 promotes pre-mRNA splicing in yeast and defines nonessential yeast Smd1p sequences.
abstract: Parallel investigations of yeast and metazoan pre-mRNA splicing have documented enormous complexity in the nucleic acid and protein components of the cellular splicing apparatus, the spliceosome. The degree to which yeast and metazoan spliceosomal proteins differ in composition and structure is currently unknown. In this report we demonstrate that the human small nuclear ribonucleoprotein (snRNP) polypeptide D1 complements the cell lethality, splicing deficiency, and snRNA instability phenotypes associated with a yeast smd1 null allele. Mutational analysis of yeast SMD1, guided by a comparison of the predicted yeast and human proteins, reveals that a large, nonconserved portion of Smd1p is dispensable for biological activity. These observations firmly establish D1 as an essential component of the cellular splicing apparatus and suggest that yeast and metazoa are remarkably similar in the polypeptides guiding early snRNP assembly.
authors.affiliation: T.H. Morgan School of Biological Sciences, University of Kentucky, Lexington 40506-0225.
authors.forename: B C
authors.initials: BC
authors.lastname: Rymond
authors.forename: L A
authors.initials: LA
authors.lastname: Rokeach
authors.forename: S O
authors.initials: SO
authors.lastname: Hoch
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001324:Autoantigens; D001483:Base Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D005800:Genes, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing / Q000187:drug effects*; D012342:RNA, Small Nuclear / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017381:Spliceosomes / Q000378:metabolism; D055517:snRNP Core Proteins
chemical_list: D001324:Autoantigens; D005656:Fungal Proteins; D012322:RNA Precursors; D012342:RNA, Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; C079499:SMD1 protein, S cerevisiae; C526409:SNRPD1 protein, human; D029701:Saccharomyces cerevisiae Proteins; D055517:snRNP Core Proteins