Research, Research Reports
Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae
Joep Schothorst1,2, Griet Van Zeebroeck1,2 and Johan M. Thevelein1,2
We now show that the yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter Zrt1 function as transceptors for the micronutrients iron and zinc. We show that replenishment of iron to iron-starved cells or zinc to zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase activity, a well-established PKA target.
Balanced CoQ6 biosynthesis is required for lifespan and mitophagy in yeast
Isabel González-Mariscal, Aléjandro Martín-Montalvo, Cristina Ojeda-González, Adolfo Rodríguez-Eguren, Purificación Gutiérrez-Ríos, Plácido Navas, and Carlos Santos-Ocaña
In brief, we show that, in yeast, Ptc7 modulates the adaptation to respiratory metabolism by dephosphorylating Coq7 to supply newly synthesized CoQ6, and by activating mitophagy to remove defective mitochondria at stationary phase, guaranteeing a proper CLS in yeast.
Mutational analysis of fructose-1,6-bis-phosphatase FBP1 indicates partially independent functions in gluconeogenesis and sensitivity to genotoxic stress
Ali Ghanem, Ana Kitanovic, Jinda Holzwarth, Stefan Wölfl
Our results support predicted vital roles of several fructose-1,6-bisphosphatase residues for enzymatic activity and led to the identification of residues indispensable for the MMS-sensitizing effect. Despite an overlap between these two properties, careful analysis revealed two mutations, Asn75 and His324, which decouple the enzymatic activity and the MMS-sensitizing effect, indicating two distinctive biological activities linked in this key gluconeogenesis enzyme.
The copper transport-associated protein Ctr4 can form prion-like epigenetic determinants in Schizosaccharomyces pombe
Theodora Sideri1, Yoko Yashiroda2, David A. Ellis1, María Rodríguez-López1, Minoru Yoshida2, Mick F. Tuite3 & Jürg Bähler1
Ctr4 exhibits multiple features diagnostic of other fungal prions and is the first example of a prion in fission yeast. These findings suggest that transmissible protein-based determinants of traits may be more widespread among fungi.
Improvement of biochemical methods of polyP quantification
Samuel Bru1, Javier Jiménez1, David Canadell2,#, Joaquín Ariño2, Josep Clotet1
As the main output of this evaluation we propose a straightforward and robust procedure that can be used as gold standard protocol for cellular polyP purification and determination from unicellular organisms, thus providing consistency to measurements and facilitating inter-laboratory comparisons and biological interpretation of the results.
Bax mitochondrial relocation is linked to its phosphorylation and its interaction with Bcl-xL
David Garenne1,2, Thibaud T. Renault1,3, Stéphen Manon1
The heterologous expression of Bax, and other Bcl-2 family members, in the yeast Saccharomyces cerevisiae, has proved to be a valuable reporter system to investigate the molecular mechanisms underlying their interaction with mitochondria. Our data provide the molecular basis for a model of dynamic equilibrium for Bax localization and activation, regulated both by phosphorylation and Bcl-xL.
Impact of histone H4K16 acetylation on the meiotic recombination checkpoint in Saccharomyces cerevisiae
Santiago Cavero1,2, Esther Herruzo1, David Ontoso1,3 and Pedro A. San-Segundo1
In meiotic cells, the pachytene checkpoint or meiotic recombination checkpoint is a surveillance mechanism that monitors critical processes, such as recombination and chromosome synapsis, which are essential for proper distribution of chromosomes to the meiotic progeny. We report here that Sas2-mediated acetylation of histone H4 at lysine 16 (H4K16ac) modulates meiotic checkpoint activity in response to synaptonemal complex defects. Our results reveal that proper levels of H4K16ac orchestrate this meiotic quality control mechanism and that Sir2 impinges on additional targets to fully activate the checkpoint.
The transcription factors ADR1 or CAT8 are required for RTG pathway activation and evasion from yeast acetic acid-induced programmed cell death in raffinose
Luna Laera1,#, Nicoletta Guaragnella1,#, Maša Ždralević1,¶, Domenico Marzulli1, Zhengchang Liu2 and Sergio Giannattasio1
Yeast Saccharomyces cerevisiae grown on glucose undergoes programmed cell death (PCD) induced by acetic acid (AA-PCD), but evades PCD when grown in raffinose. This is due to concomitant relief of carbon catabolite repression (CCR) and activation of mitochondrial retrograde signaling. In this work, we investigated the relationships between the RTG and CCR pathways in the modulation of AA-PCD sensitivity under glucose repression or de-repression conditions. Our data show that simultaneous mitochondrial retrograde pathway activation and SNF1-dependent relief of CCR have a key role in central carbon metabolism reprogramming which modulates the yeast acetic acid-stress response.
The ubiquitin-conjugating enzyme, Ubc1, indirectly regulates SNF1 kinase activity via Forkhead-dependent transcription
Rubin Jiao1, Liubov Lobanova1, Amanda Waldner1, Anthony Fu1, Linda Xiao1, Troy A. Harkness1, and Terra G. Arnason1,2
The SNF1 kinase class of serine/threonine kinases, which includes the AMP-dependent protein kinase (AMPK) in other systems, are of widespread interest because of their important roles in glucose homeostasis, stress resistance, and aging. Our goal was to identify discrete ubiquitin-conjugating enzymes that are involved in SNF1 kinase activity in response to glucose levels and anticipated revealing those which are involved in Snf1-Ub attachment. Here, we report that the cell cycle and stress-related E2, Ubc1, indirectly affects SNF1 kinase activity not through stability, but through upstream events.
A time-resolved high-throughput screening of fission yeast deletion mutants for oxidative stress resistance
July 22, 2026
By capturing dynamic trajectories rather than static outcomes, this study exposes hidden layers of growth under oxidative stress and identifies new genetic determinants of cellular resilience in fission yeast.
Microwave-assisted preparation of yeast cells for ultrastructural analysis by electron microscopy
November 18, 2024
Budding yeast Saccharomyces cerevisiae is widely used as a model organism to study the biogenesis and architecture of organellar membranes, which can be visualized by transmission electron microscopy (TEM).
Direct detection of stringent alarmones (pp)pGpp using malachite green
August 5, 2024
In this study, we demonstrate the surprising discovery of a commercially available, low-cost malachite green (MG) detection kit, originally designed for orthophosphate (Pi) detection, for detecting (p)ppGpp and its analogues, especially pGpp
Unresolved mystery of cyclic nucleotide second messengers, periplasmic acid phosphatases and bacterial natural competence
July 18, 2024
In this study we aimed to identify the promotors responsible for the expression of the non-specific acid phosphatase AphA during different starvation conditions, to confirm the requirement of the cAMP-dependent CRP regulon for aphA expression, and to finally identify regulators of its expression.
Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2
August 8, 2023
We show here that apart from its effector role for Elongator-dependent tRNA modification in yeast, Kti13 alias Dph8 also operates in step one of the diphthamide modification pathway.
Atg1, a key regulator of autophagy, functions to promote MAPK activation and cell death upon calcium overload in fission yeast
May 10, 2023
Here, we provide evidence that the fission yeast Atg1 regulates cell death responses upon intracellular calcium load in addition to its role in promoting Pmk1 MAPK.
Investigating the role of G-quadruplexes at Saccharomyces cerevisiae telomeres
May 19, 2022
In this study, the authors examine the in vivo relevance of telomeric G-quadruplexes in the budding yeast Saccharomyces cerevisiae by expressing a mutant telomerase RNA subunit (tlc1-tm) that introduces mutant telomeric repeats instead to the distal ends of telomeres. (...)