title: Isolation of Saccharomyces cerevisiae RNase T1 hypersensitive (rns) mutants and genetic analysis of the RNS1/DSL1 gene.
abstract: Overexpression of the rntA cDNA encoding RNase T1 derived from A. oryzae causes severe growth inhibition in S. cerevisiae. We previously reported that most S. cerevisiae mutant strains defective in translocation into the ER, ER-Golgi transport and vacuole formation exhibited hypersensitivity to expression of RNase T1. Screening for S. cerevisiae mutants that showed RNase T1 hypersensitivity resulted in the isolation of 38 (rns) mutant strains. Some of these mutants showed a variety of phenotypes including temperature-sensitive growth, hypersensitivity to G418, defect in invertase glycosylation and fragmented vacuoles. We identified the genes mutated in three of the rns mutants, rns1, rns2, and rns3, as DSL1, UMP1, and SEC17, respectively. Fluorescence microscopic observation showed that GFP or myc-tagged Rns1p was localized at the nuclear region in the cell. Two-hybrid screening revealed the interaction of Rns1p with a transcription factor Cin5p and a functionally unknown Ylr440cp. It was observed that HA-tagged Ylr440cp was localized to the ER and nuclear envelope.
authors.affiliation: Department of Biotechnology, The University of Tokyo, Tokyo, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Unno
authors.forename: Gen
authors.initials: G
authors.lastname: Nonaka
authors.forename: Harushi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kitamoto
mesh_terms: D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D016296:Mutagenesis; D006163:Ribonuclease T1 / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques
chemical_list: D004271:DNA, Fungal; D049452:Green Fluorescent Proteins; D006163:Ribonuclease T1