title: Isolation of an extragenic suppressor of the rna1-1 mutation in Saccharomyces cerevisiae.
abstract: The small GTPase Ran is essential for nucleocytoplasmic transport of macromolecules. In the yeast Saccharomyces cerevisiae, Rna1p functions as a Ran-GTPase activating protein (RanGAP1). Strains carrying the rna1-1 mutation exhibit defects in nuclear transport and, as a consequence, accumulate precursor tRNAs. We have isolated two recessive suppressors of the rna1-1 mutation. Further characterization of one of the suppressor mutations, srn10-1, reveals that the mutation (i) can not bypass the need for Rna1p function and (ii) suppresses the accumulation of unspliced pre-tRNA caused by rna1-1. The SRN10 gene is not essential for cell viability and encodes an acidic protein (pI = 5.27) of 24.8 kDa. Srn10p is located in the cytoplasm, as determined by indirect immunofluorescence microscopy. Two-hybrid analysis reveals that there is a physical interaction between Srn10p and Rna1p in vivo. Our results identify a protein that interacts with the yeast RanGAP1.
authors.affiliation: Department of Microbiology, College of Natural Sciences, Seoul National University, Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Hong
authors.forename: Y S
authors.initials: YS
authors.lastname: Yi
authors.forename: S S
authors.initials: SS
authors.lastname: Koh
authors.forename: O K
authors.initials: OK
authors.lastname: Park
authors.forename: H S
authors.initials: HS
authors.lastname: Kang
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D020690:GTPase-Activating Proteins; D016153:Genes, Suppressor; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins; D020690:GTPase-Activating Proteins; C060997:RNA1 protein, S cerevisiae; C115245:SRN2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins