Inheritance of suppressors of the drug sensitivity of aNSR1 deleted yeast strain

Zabetakis, Dan

doi:10.1002/1097-0061(20000915)16:12<1147::aid-yea610>3.0.co;2-m

Cited by 10 publications

(1 citation statement)

References 45 publications

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“…This antibiotic interferes with translational fidelity by targeting 18 S rRNA in the context of the 40 S ribosomal subunit (16,26). It is believed that the sensitivity of these mutants arises from improper assembly of the 40 S subunits, leaving the ribosome more accessible to, or more strongly affected by, paromomycin (27). The fact that hcr1⌬ cells are hypersensitive to paromomycin further supports the involvement of eIF3j in promoting 40 S subunit biogenesis.…”

Section: Eif3j/hcr1p Has a Role In 40 S Ribosome Biogenesis-eif3j/mentioning

confidence: 95%

Dual Function of eIF3j/Hcr1p in Processing 20 S Pre-rRNA and Translation Initiation

Valášek¹,

Hašek²,

Nielsen³

et al. 2001

Journal of Biological Chemistry

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eIF3j/Hcr1p, a protein associated with eIF3, was shown to bind to, and stabilize, the multifactor complex containing eIFs 1, 2, 3, and 5 and Met-tRNA i Met , whose formation is required for an optimal rate of translation initiation. Here we present evidence that eIF3j/Hcr1p is an RNA binding protein that enhances a late step in 40 S ribosome maturation involving cleavage of the 20 S precursor of 18 S rRNA in the cytoplasm. Immunofluorescence staining shows that eIF3j/Hcr1p is localized predominantly in the cytoplasm. The hcr1⌬ mutant exhibits a decreased amount of 40 S subunits, hypersensitivity to paromomycin, and increased levels of 20 S pre-rRNA. Combining the hcr1⌬ mutation with drs2⌬ or rps0a⌬, deletions of two other genes involved in the same step of 40 S subunit biogenesis, produced a synthetic growth defect. p35, the human ortholog of eIF3j/Hcr1p, partially complemented the slow growth phenotype conferred by hcr1⌬ when overexpressed in yeast. heIF3j/p35 was found physically associated with yeast eIF3 and 43 S initiation complexes in vitro and in vivo. Because it did not complement the 40 S biogenesis defect of hcr1⌬, it appears that heIF3j can substitute for eIF3j/Hcr1p only in translation initiation. We conclude that eIF3j/Hcr1p is required for rapid processing of 20 S to 18 S rRNA besides its role in translation initiation, providing an intriguing link between ribosome biogenesis and translation.Once the genetic information is transcribed into mRNA, its final translation into a protein requires charged tRNAs and the translation machinery, consisting of the ribosome and soluble translation factors. The assembly of 40 S and 60 S ribosomal subunits occurs primarily in a specialized subnuclear compartment termed the nucleolus, but the final steps occur in the cytoplasm. A large number of proteins and small nuclear RNAs participate in ribosome biogenesis (for review see Ref. 1). In the process of translation initiation, several translation initiation factors (eIFs) 1 orchestrate the assembly of an 80 S initiation complex containing methionyl initiator tRNA (Met-tRNA i Met ) located in the P site of the ribosome and based paired with the AUG start codon in the mRNA (for review see Ref.2). Correct completion of this process is crucial for further decoding of the genetic information during the elongation phase of translation. In general, proteins acting in the ribosome assembly process do not participate in translation and vice versa. Here we describe a protein in the yeast Saccharomyces cerevisiae that is involved in the maturation of 40 S subunits and also in assembly of the 43 S preinitiation complex, an important intermediate in translation initiation. These findings may indicate that ribosome biogenesis and translation initiation are more closely coordinated processes than was previously thought.The 9.1-kb rDNA unit encoding all four rRNAs occurs in about 100 -200 copies repeated on chromosome XII of S. cerevisiae. Ribosome biogenesis begins by transcription of the rRNA genes by RNA polymerase I to produc...

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Section: Eif3j/hcr1p Has a Role In 40 S Ribosome Biogenesis-eif3j/mentioning

confidence: 95%

Dual Function of eIF3j/Hcr1p in Processing 20 S Pre-rRNA and Translation Initiation

Valášek¹,

Hašek²,

Nielsen³

et al. 2001

Journal of Biological Chemistry

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Current Awareness

2000

Yeast

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2‐Methyl‐6‐arylimidazo[1,2‐a]pyrazin‐3(7H)‐ones with a substituent such as phenyl, 4‐methoxyphenyl or 4‐trifluoromethoxyphenyl at the 6‐position of the imidazo[1,2‐a]pyrazin‐3(7H)‐one ring system, produced chemiluminescence emission in mixtures of water and DMF and in several mixtures of MeOH and DMF under neutral conditions. Under these protic luminescence conditions, the respective light emissions were generated from neutral singlet excited‐state molecules. The electron‐donating effect of the 4‐methoxy substituent on the phenyl group increased the efficiency of the neutral singlet excited state formation, whereas non‐substitution and a 4‐trifluoromethoxy group having no electron donating ability decreased the efficiency. The compound having the electron‐donating methoxy group substituent showed two chemiluminescence emitters, which generated light at λmax 410–420 nm and 460 nm. It was determined that the neutral molecules in the excited state generating light emission at the shorter wavelengths are neutral singlet excited‐state molecules suitable for highly efficient singlet excited‐state formation. A role of the electron‐donating effect of the methoxy group is postulated to be generation of the special neutral singlet excited‐state molecules. Copyright © 1999 John Wiley & Sons, Ltd.

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Genetic interactions of yeast NEP1 (EMG1), encoding an essential factor in ribosome biogenesis

Schilling

Peifer

Buchhaupt

et al. 2012

Yeast

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Nep1 methylates the hypermodified c1191 base of 18S rRNA and has an additional essential function during ribosome biogenesis. It is strongly conserved in eukaryotes and a point mutation causes the human Bowen-Conradi syndrome. To identify Δnep1-specific genetic interactions, viable deletions were screened genome-wide (SGA). Due to its essential function, we used, for the first time, query strain (Δnep1) with two additive suppressor conditions (mcRPS19B, nop6-1). Nep1 interacting genes correspond to ribosome biogenesis (RPS18A, RPS18B, RRP8, EFG1, UTP30), to ribosome quality control (UBP3, BRE5, UBP6) and to ribosome functional control (DOM34, no-go decay). Deletions in ribosome quality and functional control genes were synthetically sick with Δnep1. They cope with malfunctions and the respective deletions strengthen the Δnep1 growth deficiency. Except for Δrps18b, deletions in the identified ribosome biogenesis genes were synthetically lethal with Δnep1. While the synthetic lethalities of Δrrp8 and Δefg1 may result from additive defects, the Δutp30 deletion seems to be in close functional relationship. The Δutp30 deletion itself has no phenotype but it enforced all nep1-1 ts mutant phenotypes. Furthermore, its overexpression partially restored the nep1-1 ts growth deficiency. Our genetic and biochemical data suggest that Utp30 and Nep1 act together during pre-ribosomal complex formation and, along with Rps18, provide the surface for the Rps19 assembly to the 90S pre-ribosome.

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Inheritance of suppressors of the drug sensitivity of aNSR1 deleted yeast strain

Cited by 10 publications

References 45 publications

Dual Function of eIF3j/Hcr1p in Processing 20 S Pre-rRNA and Translation Initiation

Dual Function of eIF3j/Hcr1p in Processing 20 S Pre-rRNA and Translation Initiation

Current Awareness

Genetic interactions of yeast NEP1 (EMG1), encoding an essential factor in ribosome biogenesis

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