Genetic interactions of ribosome maturation factors Yvh1 and Mrt4 influence mRNA decay, glycogen accumulation, and the expression of early meiotic genes in Saccharomyces cerevisiae

Abstract

The Saccharomyces cerevisiae Yvh1, a dual-specificity protein phosphatase involved in glycogen accumulation and sporulation, is required for normal vegetative growth. To further elucidate the role of Yvh1, we generated dominant mutants suppressing the slow growth caused by YVH1 disruption. One of the mutant alleles, designated as SVH1-1 (suppressor of Δyvh1 deletion), was identical to MRT4 (mRNA turnover) that contained a single-base substitution causing an amino acid change from Gly(68) to Asp. Mrt4(G68D) restored the deficiencies in growth and rRNA biogenesis that occurs in absence of Yvh1. Here, we report that the interaction between Mrt4 and Yvh1 is also essential for normal glycogen accumulation and mRNA decay as well as the induction of sporulation genes IME2, SPO13 and HOP1. The Mrt4(G68D) could restore the plethora of phenotypes we observed in absence of Yvh1. We found that Yvh1 is not essential for wild-type induction of the transcriptional regulator of these genes, IME1, suggesting that either translation or post-translational modification to activate Ime1 has been compromised. Since a defect in ribosome biogenesis in general can be related to other various defects, the ribosome biogenesis defect caused by absence of Yvh1 might be an indirect cause of observed phenotypes.

MoYvh1 subverts rice defense through functions of ribosomal protein MoMrt4 in Magnaporthe oryzae

“…cerevisiae nucleolar protein Mrt4. The yeast Mrt4 contains a Gly residue at position 68 whose substitution with Asp or Glu could suppress the growth defect of the Δ yvh1 strain [ 5 , 23 , 24 ]. To investigate whether MoYvh1 shares functional conservation with S .…”

“…This finding is consistent with studies in S . cerevisiae in which the deletion of MRT4 causes defects in growth but no blocking in ribosome synthesis [ 5 , 11 , 23 , 35 ].…”

“…S . cerevisiae Yvh1 is known to also have a role in ribosome maturation and function [ 5 ]. In eukaryotic cells, mature ribosomes are composed of five different proteins that include Rpp0 and two copies of each of proteins P1 and P2 [ 6 – 8 ].…”

Characterization of Single Gene Deletion Mutants Affecting Alternative Oxidase Production in Neurospora crassa: Role of the yvh1 Gene

“…The strain carries a deletion of the yvh1 gene. The YVH1 protein is known to be involved in ribosome assembly in other systems, and loss of the functional protein results in an array of phenotypes [ 39 , 40 , 41 , 42 , 43 ]. However, to our knowledge, no previous studies have examined the effect of yvh1 mutations on AOX expression.…”

Emerging Roles of Atypical Dual Specificity Phosphatases in Cancer

“…In yvh1 null yeast strains Mrt4p remained associated with the cytoplasmic 60S subunits preventing the assemblage of the P0/P1/P2 proteins that form the ribosomal stalk [78]. Further supporting a genetic interaction between YVH1 and MRT4, specific mutations of mtr4 suppressed all yvh1Δ phenotypes, suggesting that the pleiotropic phenotypes associated with yvh1Δ strains may be an indirect consequence of aberrant ribosome maturation [83].…”