The Saccharomyces cerevisiae protein Stm1p facilitates ribosome preservation during quiescence

Dyke, Natalya Van; Chanchorn, Ekkawit; Dyke, Michael W. Van

doi:10.1016/j.bbrc.2012.11.078

Cited by 36 publications

(46 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3b). As expected, awr5 expression resulted in a decrease of the levels of the TOR-activated STM1 and NSR1 genes, which are involved in yeast growth2728. In contrast, the levels of the TOR-repressed GAP1 and MEP2 , which control nitrogen catabolite repression29, increased in response to awr5 expression.…”

Section: Resultssupporting

confidence: 54%

The effector AWR5 from the plant pathogen Ralstonia solanacearum is an inhibitor of the TOR signalling pathway

Popa

Espeso-Gil

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Bacterial pathogens possess complex type III effector (T3E) repertoires that are translocated inside the host cells to cause disease. However, only a minor proportion of these effectors have been assigned a function. Here, we show that the T3E AWR5 from the phytopathogen Ralstonia solanacearum is an inhibitor of TOR, a central regulator in eukaryotes that controls the switch between cell growth and stress responses in response to nutrient availability. Heterologous expression of AWR5 in yeast caused growth inhibition and autophagy induction coupled to massive transcriptomic changes, unmistakably reminiscent of TOR inhibition by rapamycin or nitrogen starvation. Detailed genetic analysis of these phenotypes in yeast, including suppression of AWR5-induced toxicity by mutation of CDC55 and TPD3, encoding regulatory subunits of the PP2A phosphatase, indicated that AWR5 might exert its function by directly or indirectly inhibiting the TOR pathway upstream PP2A. We present evidence in planta that this T3E caused a decrease in TOR-regulated plant nitrate reductase activity and also that normal levels of TOR and the Cdc55 homologues in plants are required for R. solanacearum virulence. Our results suggest that the TOR pathway is a bona fide T3E target and further prove that yeast is a useful platform for T3E function characterisation.

show abstract

Section: Resultssupporting

confidence: 54%

The effector AWR5 from the plant pathogen Ralstonia solanacearum is an inhibitor of the TOR signalling pathway

Popa

Espeso-Gil

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…While it is coincidental that the only intact copies of PEP3 and STM1 in the overexpression library were isolated on the same contig—pGP564-YGM18p06—assessment of growth rate and lag phase duration was a helpful step in distinguishing their individual contributions to acetic acid “resistance.” Our finding that STM1 overexpression both increased growth rate and reduced lag phase duration in acetic acid-stressed cells is consistent with previous work that showed a role for STM1 in protecting a subset of ribosomes from degradation during autophagy (Van Dyke et al 2006, 2013). We speculate that such cells are more likely to begin growth sooner and to grow faster once they have recovered from the initial acetic acid shock than cells whose ribosomes have been largely degraded.…”

Section: Discussionsupporting

confidence: 93%

“…Because STM1 was also on the pGPM18p06 contig—but not on others in the library—and had previously been implicated in protecting ribosomes from nutritional starvation-induced degradation (Van Dyke et al 2006, 2013), we cloned STM1 into pGP564 and constructed S288c leu2 Δ/pGP564- STM1 to evaluate its individual contribution to overcoming acetic acid-induced stress. In the absence of acetic acid, the lag phase of S288c leu2 Δ / pGP564- STM1 was about 70 % longer than that of the empty vector control strain and its growth rate was about 12 % slower.…”

Section: Resultsmentioning

confidence: 99%

PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress

Ding

Holzwarth

Bradford

et al. 2015

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

In fungi, two recognized mechanisms contribute to pH homeostasis: the plasma membrane proton-pumping ATPase that exports excess protons and the vacuolar proton-pumping ATPase (V-ATPase) that mediates vacuolar proton uptake. Here, we report that overexpression of PEP3 which encodes a component of the HOPS and CORVET complexes involved in vacuolar biogenesis, shortened lag phase in Saccharomyces cerevisiae exposed to acetic acid stress. By confocal microscopy, PEP3-overexpressing cells stained with the vacuolar membrane-specific dye, FM4-64 had more fragmented vacuoles than the wild-type control. The stained overexpression mutant was also found to exhibit about 3.6-fold more FM4-64 fluorescence than the wild-type control as determined by flow cytometry. While the vacuolar pH of the wild-type strain grown in the presence of 80 mM acetic acid was significantly higher than in the absence of added acid, no significant difference was observed in vacuolar pH of the overexpression strain grown either in the presence or absence of 80 mM acetic acid. Based on an indirect growth assay, the PEP3-overexpression strain exhibited higher V-ATPase activity. We hypothesize that PEP3 overexpression provides protection from acid stress by increasing vacuolar surface area and V-ATPase activity and, hence, proton-sequestering capacity.

show abstract

“…Interaction with both subunits likely accounts for their ability to promote subunit association (Correia et al, 2004), possibly to sequester ribosomes during stress to protect them from degradation (e.g. van Dyke et al, 2013). Stm1 was also suggested to inhibit translation (Balagopal and Parker, 2011), which would be consistent with the occlusion of the mRNA-binding channel.…”

Section: Discussionmentioning

confidence: 99%

Multiple Mechanisms of Reinitiation on Bicistronic Calicivirus mRNAs

2015

View full text Add to dashboard Cite

Reinitiation is a strategy used by viruses to express several cistrons from one mRNA. Although extremely weak after translation of long ORFs on cellular mRNAs, reinitiation occurs efficiently on subgenomic bicistronic calicivirus mRNAs, enabling synthesis of minor capsid proteins. The process is governed by a short element upstream of the restart AUG designated “termination upstream ribosomal binding site” (TURBS). It contains the conserved Motif 1 complementary to h26 of 18S rRNA, displayed in the loop of a hairpin formed by species-specific Motifs 2/2*. To determine the advantages conferred on reinitiation by TURBS, we reconstituted this process in vitro on two model bicistronic calicivirus mRNAs. We found that post-termination ribosomal tethering of mRNA by TURBS allows reinitiation by post-termination 80S ribosomes, and diminishes dependence on eIF3 of reinitiation by recycled 40S subunits, which can be mediated either by eIFs 2/1/1A or by Ligatin following ABCE1-dependent or -independent splitting of post-termination complexes.

show abstract

The Saccharomyces cerevisiae protein Stm1p facilitates ribosome preservation during quiescence

Cited by 36 publications

References 26 publications

The effector AWR5 from the plant pathogen Ralstonia solanacearum is an inhibitor of the TOR signalling pathway

The effector AWR5 from the plant pathogen Ralstonia solanacearum is an inhibitor of the TOR signalling pathway

PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress

Multiple Mechanisms of Reinitiation on Bicistronic Calicivirus mRNAs

Contact Info

Product

Resources

About