Molecular Physiology of the Cell

Florent Corillon received an assistant fellowship from ULB

A commission of ULB selected the application of Forent Corillon for a one-year PhD “assistant” fellowship. Florent, who previously did his master thesis in the lab on the structure-function relatioships of the Ssy1 sensor, will now investigate the signalling properties of the yeast Gap1 permease. He will also be involved in the supervision of practical works for students. Congratulations to him and good luck with this new project.

Nathan Fraikin joined the lab

We are pleased to welcome a new pregraduate student, Nathan Fraikin, in the lab. During his master thesis, Nathan will study the role of phosphorylation in the endocytosis and intracellular traffic of the yeast Gap1 permease.

“Yeast Genetics meeting” in Seattle

B André attended the last “Yeast Genetics meeting” which took place July 29-August 3 in Seattle (USA) at the Washington University. The very interesting program also included a special lecture by George Church (Harvard univ.) about synthetic biology. Below pictures of the campus and Seattle.

Summer Biopark News

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Novel ubiquitylation pathway for Gap1 permease published in JBC

The editors of the Journal of Biological Chemistry informed us that our last paper entitled “Stress conditions promote yeast Gap1 permease ubiquitylation and downregulation via the arrestin-like Bul and Aly proteins” has been accepted for publication. This work, carried out by Myriam Crapeau and Ahmad Merhi, shows that inhibition of the TORC1 kinase complex, or any stress condition, stimulates ubiquitylation and endocytosis of the yeast Gap1 permease via a mechanism different from the one we previously described for the amino-acid induced Gap1 downregulation (Merhi and André, 2012).

Kassem Ghaddar received his PhD diploma

On April 3rd, Kassem Ghaddar publicly presented his PhD work entitled “Structural analysis of yeast amino acid transporters : substrate binding and substrate-induced endocytosis” and received his PhD diploma. A great moment for Kassem, who was surrounded by colleages, friends, and family members. Kassem will soon undertake a postdoc in another lab in Begium. Thanks a lot to him for his key contribution to our study of yeast amino acid transporters, and good luck in everything.

Spring Biopark News

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“International Cystinosis Research Foundation” symposium (Irvine, USA)

Melody Cools and Bruno André attended and contributed to the 4th Symposium organized by the Cystinosis Research Foundation on March 6-7, 2014 at the Beckman Center of the National Academies of Engineering and Science, Irvine, California. The mission of this conference was to unite CRF funded researchers in an effort to encourage collaboration and accelerate the research process. The keynote speaker at the symposium was Dr. Ana Maria Cuervo, a world renowned expert in the field of autophagy.

First “structural rewiring” of a yeast amino acid transporter published in JBC

A study by Ghaddar, Krammer et al. carried out in collaboration with Martine Prévost (ULB, Structure and Function of Biological Membranes) and entitled “Converting the yeast arginine Can1 permease into a lysine permease” has been published in The Journal of Biological Chemistry. This work presents our first structural analysis of a yeast amino acid transporter (see figure). Modelling of the substrate binding site and insertion by mutagenesis of amino-acid substitutions allowed us to switch the substrate-specificity of the permease. This opens the interesting perspective to solve the structural code of amino acid recognition by yeast amino acid permeases and to establish links with regulation.

Milligrams of Gap1 purified

In a novel paper by Debailleul et al. published in Microbial Cell Factories in collaboration with Dr. Cédric Govaerts (Lab of Structure and function of biological membranes, ULB), we report the development of a new inductible expression system in yeast based on the promoter of the GAP1 gene encoding the general amino acid permease. Using this system, a protocol has been implemented to purify in a few days milligrams of the Gap1 permease from yeast cells. This opens important perspectives for future works on the structure-function relationships of this membrane transporter.

Nitrogen catabolite repressible GAP1 promoter, a new tool for efficient recombinant protein production in S. cerevisiae. Debailleul F, Trubbia C, Frederickx N, Lauwers E, Merhi A, Ruysschaert JM, André B, Govaerts C.
Microb Cell Fact. 2013 Dec 26;12(1):129.