Study on yeast vacuolar arginine transporters published in PLoS Genetics


In a novel article entitled “Nitrogen coordinated import and export of arginine across the yeast vacuolar membrane” just published in PLoS Genetics, we report an extensive study of the arginine transporters  localized at the yeast vacuolar membrane. We describe Vsb1 as a novel  transmembrane protein acting as the main vacuolar arginine import system. We also report that Ypq2, a vacuolar transporter homologous to the human lysosomal PQLC2 protein, importantly contributes to arginine export from the vacuole where the amino acid is stored at high levels Finally, we provide clear evidence that Vsb1 and Ypq2 are inversely regulated by nitrogen supply. This paper is signed as a first author by Melody Cools who did her PhD in our lab and who established the methodology needed for conducting this study. Melody is now scientist at the Labiris institute where she pursues her research work on yeast vacuolar transporters and their regulation.  This work has benefited from the valuable collaboration of Dr. Isabelle Georis (Labiris) and Pr. Alexander DeLuna (Guanajuato, Mexico).          

Coronavirus crisis: lab research activity finally resumed

On March 20, our lab was closed, like all others in our university. Since then, we regularly had lab meetings and journal clubs via Teams or Zoom, online tools we never used before. Three of us (Catherine, Simon and Bruno) joined the platform that was rapidly implemented in our institute (thanks to efforts of our colleagues C. Gueydan and G. De Muylder) to carry out coronavirus qRT-PCR tests for hospitals and nursing houses around Charleroi.

From May 6th, the lab is open again, with application of strict distance and hygiene rules. Thanks very much to Catherine who had in charge to organize this and who did an incredible job to collect masks for everyone, define safety rules and equip each room. Most of us could thus take over experiments which is good news. Hopefully normal life will be back soon.

Nadia Pia Guarini obtained a FRIA fellowship

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Nadia Pia Guarini was informed by the FNRS that she’s among the laureates of the 2019 competition for FRIA fellowships. Nadia obtained her master diploma in the University of Firenze (Italy). She moved in February 2019 to our lab where she already contributed to the research topic of her PhD, namely the regulation of the TOR kinase complex 1 (TORC1) by the plasma membrane H+-ATPase in yeast. 

 

 

 

Article on ubiquitylation and endocytosis of human LAT1 transporter published in Scientific Reports

LAT1 endocytosis
A novel article published in Scientific Reports by C. Barthelemy and B. André describes conditions triggering rapid endocytosis and degradation of the human LAT1/SLC7A5 amino acid transporter in human HeLa cells. The study further shows that the signal eliciting this downregulation is ubiquitin. The modification occurs on a group of three lysines in the cytosolic N-terminal tail of the transporter and is mediated by the Nedd4-2 ubiquitin ligase.  Future work will determine the importance of this mechanism in normal and tumour cells, where LAT1/SLC7A5 plays an important role, in particular through control of the TOR kinase complex 1 (mTORC1). 

“Yeast Research: Origins, Insights, Breakthroughs” meeting at Cold Spring Harbor

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Bruno André attended the “Yeast Research: Origins, Insights, Breakthroughs” (October 23-26) meeting organized by the Cold Spring Harbor laboratory. The meeting was the “yeast” version of a special meeting series organized by Mila Pollock and dedicated to the history of sciences based on model organisms and to the latest advances in the field. The communication of B. André dealt with the pioneering role of Marcelle Grenson (ULB) in the development of yeast genetics in Belgium in the early 60s, and the recent data of the lab about TORC1 control in yeast. 

Cecilia Primo received a Marie Skłodowska-Curie postdoc ULB grant for joining the lab

Cecilia Primo
Dr. Cecilia Primo Planta joined the lab as a postdoc supported by the Marie Curie cofund IF@ULB. Cecilia comes from Valencia (Spain) where she did her PhD under the supervision of Pr. Lyne Yennusch (Institute of Molecular and Cellular Biology of Plants) about the tight relationships between potassium and TORC1 in yeast. She then moved to Houston (USA) where she did a postdoc in the lab of Pr. KD Hirschi (Baylor College of Medicine, Children’s Nutrition Research Center) where she investigated miRNAs and Type 1 H+-pumping pyrophosphatases in the plant Arabidopsis thaliana. She has now joined the lab for working on the role of plasma membrane H+-ATPases in TORC1 regulation.

Methodology article published in 2nd edition of « Yeast Systems Biology »

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An article published in collaboration with our colleague Andreas Mayer (Lausanne university) has just been released in the 2nd edition of the book « Yeast Systems Biology ». The paper signed as first author by our former PhD student Melody Cools (now in the Labiris group of Dr. Isabelle Georis, Brussels) describes detailed protocols for measuring the activity of plasma membrane and vacuolar transporters of yeast. We hope that this methodology article will be helpful for all groups interested in membrane transport and wishing to implement these techniques in their lab.  

2019 “International Yeast Genetics and Molecular Biology Meeting” in Göteborg (Sweden)

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Elie Saliba, Minos Evangelinos, and Bruno André attended the 24th “International Yeast Genetics and Molecular Biology Meeting” which was held in Göteborg (Sweden), from August 18 to 22. Elie Saliba presented a poster about the role of Pma1 in TORC1 control and Melody Cools (now in I. Georis’s lab) presented another about the arginine transporters of the yeast vacuole. The meeting was scientifically intense and of top interest, and the programme also included a lecture by Roger Kornberg (Nobel Prize). The meeting also offered a great opportunity to meet again many colleagues and friends.   

Céline Barthélemy received her PhD diploma

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On July 1rst, Céline Barthélemy publicly presented her PhD work and successfully received her diploma. Her research dealt with the mechanisms promoting endocytosis of the human LAT1 amino acid transporter in HeLa cancer cells. Céline could show that LAT1 endocytosis is triggered by ubiquitylation of the transporter via the Nedd4-2 ubiquitin ligase enzyme. She also investigated the influence of FTY720, an immunosuppressant compound, and found that it also provokes the endocytosis of LAT1, and of several amino acid permeases in yeast.  

 

Team building day at the “Eau d’Heure” site

For this year team-bilding day, we visited the “Eau d’Heure” site and had a very pleasant long walk followed by a lunch.