Université de Fribourg

An ATP-dependent partner switch links flagellar C-ring assembly with gene expression

Blagotinsek, Vitan ; Schwan, Meike ; Steinchen, Wieland ; Mrusek, Devid ; Hook, John C. ; Rossmann, Florian ; Freibert, Sven A. ; Kratzat, Hanna ; Murat, Guillaume ; Kressler, Dieter ; Beckmann, Roland ; Beeby, Morgan ; Thormann, Kai M. ; Bange, Gert

In: Proceedings of the National Academy of Sciences, 2020, vol. 117, no. 34, p. 20826–20835

Bacterial flagella differ in their number and spatial arrangement. In many species, the MinD-type ATPase FlhG (also YlxH/FleN) is central to the numerical control of bacterial flagella, and its deletion in polarly flagellated bacteria typically leads to hyperflagellation. The molecular mechanism underlying this numerical control, however, remains enigmatic. Using the model species Shewanella...

Université de Fribourg

Conformational proofreading of distant 40S ribosomal subunit maturation events by a long-range communication mechanism

Mitterer, Valentin ; Shayan, Ramtin ; Ferreira-Cerca, Sébastien ; Murat, Guillaume ; Enne, Tanja ; Rinaldi, Dana ; Weigl, Sarah ; Omanic, Hajrija ; Gleizes, Pierre-Emmanuel ; Kressler, Dieter ; Plisson-Chastang, Celia ; Pertschy, Brigitte

In: Nature Communications, 2019, vol. 10, no. 1, p. 2754

Eukaryotic ribosomes are synthesized in a hierarchical process driven by a plethora of assembly factors, but how maturation events at physically distant sites on pre- ribosomes are coordinated is poorly understood. Using functional analyses and cryo- EM, we show that ribosomal protein Rps20 orchestrates communication between two multi-step maturation events across the pre-40S subunit. Our...

Université de Fribourg

Tsr4 and Nap1, two novel members of the ribosomal protein chaperOME

Rössler, Ingrid ; Embacher, Julia ; Pillet, Benjamin ; Murat, Guillaume ; Liesinger, Laura ; Hafner, Jutta ; Unterluggauer, Julia Judith ; Birner-Gruenberger, Ruth ; Kressler, Dieter ; Pertschy, Brigitte

In: Nucleic Acids Research, 2019, p. gkz317

Dedicated chaperones protect newly synthesized ribosomal proteins (r-proteins) from aggregation and accompany them on their way to assembly into nascent ribosomes. Currently, only nine of the ∼80 eukaryotic r-proteins are known to be guarded by such chaperones. In search of new dedicated r-protein chaperones, we performed a tandem-affinity purification based screen and looked for factors...

Université de Fribourg

Nuclear import of dimerized ribosomal protein Rps3 in complex with its chaperone Yar1

Mitterer, Valentin ; Gantenbein, Nadine ; Birner-Gruenberger, Ruth ; Murat, Guillaume ; Bergler, Helmut ; Kressler, Dieter ; Pertschy, Brigitte

In: Scientific Reports, 2016, vol. 6, p. 36714

After their cytoplasmic synthesis, ribosomal proteins need to be transported into the nucleus, where they assemble with ribosomal RNA into pre-ribosomal particles. Due to their physicochemical properties, they need protection from aggregation on this path. Newly synthesized ribosomal protein Rps3 forms a dimer that is associated with one molecule of its specific chaperone Yar1. Here we report...

Université de Fribourg

The eukaryote-specific N-terminal extension of ribosomal protein S31 contributes to the assembly and function of 40S ribosomal subunits

Fernández-Pevida, Antonio ; Martín-Villanueva, Sara ; Murat, Guillaume ; Lacombe, Thierry ; Kressler, Dieter ; Cruz, Jesús de la

In: Nucleic Acids Research, 2016, vol. 44, no. 16, p. 7777–7791

The archaea-/eukaryote-specific 40S-ribosomal-subunit protein S31 is expressed as an ubiquitin fusion protein in eukaryotes and consists of a conserved body and a eukaryote-specific N-terminal extension. In yeast, S31 is a practically essential protein, which is required for cytoplasmic 20S pre-rRNA maturation. Here, we have studied the role of the N-terminal extension of the yeast S31...

Université de Fribourg

Sequential domain assembly of ribosomal protein S3 drives 40S subunit maturation

Mitterer, Valentin ; Murat, Guillaume ; Réty, Stéphane ; Blaud, Magali ; Delbos, Lila ; Stanborough, Tamsyn ; Bergler, Helmut ; Leulliot, Nicolas ; Kressler, Dieter ; Pertschy, Brigitte

In: Nature Communications, 2016, vol. 7, p. 10336

Eukaryotic ribosomes assemble by association of ribosomal RNA with ribosomal proteins into nuclear precursor particles, which undergo a complex maturation pathway coordinated by non-ribosomal assembly factors. Here, we provide functional insights into how successive structural re-arrangements in ribosomal protein S3 promote maturation of the 40S ribosomal subunit. We show that S3 dimerizes...

Université de Fribourg

Co-translational capturing of nascent ribosomal proteins by their dedicated chaperones

Pausch, Patrick ; Singh, Ujjwala ; Ahmed, Yasar Luqman ; Pillet, Benjamin ; Murat, Guillaume ; Altegoer, Florian ; Stier, Gunter ; Thoms, Matthias ; Hurt, Ed ; Sinning, Irmgard ; Bange, Gert ; Kressler, Dieter

In: Nature Communications, 2015, vol. 6, p. 7494

Exponentially growing yeast cells produce every minute >160,000 ribosomal proteins. Owing to their difficult physicochemical properties, the synthesis of assembly-competent ribosomal proteins represents a major challenge. Recent evidence highlights that dedicated chaperone proteins recognize the N-terminal regions of ribosomal proteins and promote their soluble expression and delivery to the...

Université de Fribourg

Mak5 and Ebp2 act together on early Pre-60S particles and their reduced functionality bypasses the requirement for the essential Pre-60S factor Nsa1

Pratte, Dagmar ; Singh, Ujjwala ; Murat, Guillaume ; Kressler, Dieter

In: PLoS ONE, 2013, vol. 8, no. 12, p. e82741

Ribosomes are the molecular machines that translate mRNAs into proteins. The synthesis of ribosomes is therefore a fundamental cellular process and consists in the ordered assembly of 79 ribosomal proteins (r-proteins) and four ribosomal RNAs (rRNAs) into a small 40S and a large 60S ribosomal subunit that form the translating 80S ribosomes. Most of our knowledge concerning this dynamic multi-step...

Université de Fribourg

Yar1 protects the ribosomal protein rps3 from aggregation

Koch, Barbara ; Mitterer, Valentin ; Niederhauser, Johannes ; Stanborough, Tamsyn ; Murat, Guillaume ; Rechberger, Gerald ; Bergler, Helmut ; Kressler, Dieter ; Pertschy, Brigitte

In: The journal of Biological Chemistry, 2012, p. -

2000 ribosomes have to be synthesized in yeast every minute. Therefore the fast production of ribosomal proteins, their efficient delivery to the nucleus and correct incorporation into ribosomal subunits are prerequisites for optimal growth rates. Here, we report that the ankyrin repeat protein Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized...