scholarly journals Tsr4 is a cytoplasmic chaperone for the ribosomal protein Rps2 in Saccharomyces cerevisiae

2019 ◽  
Author(s):  
Joshua J. Black ◽  
Sharmishtha Musalgaonkar ◽  
Arlen W. Johnson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Unknown Function ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Eukaryotic Ribosome ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Nonspecific Interactions ◽  
Disordered Regions

AbstractEukaryotic ribosome biogenesis requires the action of approximately 200 trans-acting factors and the incorporation of 79 ribosomal proteins (RPs). The delivery of RPs to pre-ribosomes is a major challenge for the cell because RPs are often highly basic and contain intrinsically disordered regions prone to nonspecific interactions and aggregation. To counteract this, eukaryotes developed dedicated chaperones for certain RPs that promote their solubility and expression, often by binding eukaryotic-specific extensions of the RPs. Rps2 (uS5) is a universally conserved RP that assembles into nuclear pre-40S subunits. However, a chaperone for Rps2 had not been identified. Our lab previously characterized Tsr4 as a 40S biogenesis factor of unknown function. Here, we report that Tsr4 co-translationally associates with Rps2. Rps2 harbors a eukaryotic-specific N-terminal extension that was critical for its interaction with Tsr4. Moreover, Tsr4 perturbation resulted in decreased Rps2 levels and phenocopied Rps2 depletion. Despite Rps2 joining nuclear pre-40S particles, Tsr4 appeared to be restricted to the cytoplasmic. Thus, we conclude that Tsr4 is a cytoplasmic chaperone dedicated to Rps2.

scholarly journals Tsr4 Is a Cytoplasmic Chaperone for the Ribosomal Protein Rps2 in Saccharomyces cerevisiae

2019 ◽  
Vol 39 (17) ◽  
Author(s):  
Joshua J. Black ◽  
Sharmishtha Musalgaonkar ◽  
Arlen W. Johnson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Unknown Function ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Eukaryotic Ribosome ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Nonspecific Interactions ◽  
Disordered Regions

ABSTRACT Eukaryotic ribosome biogenesis requires the action of approximately 200 trans-acting factors and the incorporation of 79 ribosomal proteins (RPs). The delivery of RPs to preribosomes is a major challenge for the cell because RPs are often highly basic and contain intrinsically disordered regions prone to nonspecific interactions and aggregation. To counteract this, eukaryotes developed dedicated chaperones for certain RPs that promote their solubility and expression, often by binding eukaryote-specific extensions of the RPs. Rps2 (uS5) is a universally conserved RP that assembles into nuclear pre-40S subunits. However, a chaperone for Rps2 had not been identified. Our laboratory previously characterized Tsr4 as a 40S biogenesis factor of unknown function. Here, we report that Tsr4 cotranslationally associates with Rps2. Rps2 harbors a eukaryote-specific N-terminal extension that is critical for its interaction with Tsr4. Moreover, Tsr4 perturbation resulted in decreased Rps2 levels and phenocopied Rps2 depletion. Despite Rps2 joining nuclear pre-40S particles, Tsr4 appears to be restricted to the cytoplasm. Thus, we conclude that Tsr4 is a cytoplasmic chaperone dedicated to Rps2.

scholarly journals Intronic non-coding RNAs within ribosomal protein coding genes can regulate biogenesis of yeast ribosome

2018 ◽  
Author(s):  
Akshara Pande ◽  
Rani Sharma ◽  
Bharat Ravi Iyengar ◽  
Vinod Scaria ◽  
Beena Pillai ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Protein ◽  
Small Rnas ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Rdna Locus ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Protein Components ◽  
Retained Introns

AbstractThe genome of the budding yeast (Saccharomyces cerevisiae) has selectively retained introns in ribosomal protein coding genes. The function of these introns has remained elusive in spite of experimental evidence that they are required for the fitness of yeast. Here, we computationally predict novel small RNAs that arise from the intronic regions of ribosomal protein (RP) coding genes in Saccharomyces cerevisiae. Further, we experimentally validated the presence of seven intronic small RNAs (isRNAs). Computational predictions suggest that these isRNAs potentially bind to the ribosomal DNA (rDNA) locus or the corresponding rRNAs. Several isRNA candidates can also interact with transcripts of transcription factors and small nucleolar RNAs (snoRNAs) involved in the regulation of rRNA expression. We propose that the isRNAs derived from intronic regions of ribosomal protein coding genes may regulate the biogenesis of the ribosome through a feed-forward loop, ensuring the coordinated regulation of the RNA and protein components of the ribosomal machinery. Ribosome biogenesis and activity are fine-tuned to the conditions in the cell by integrating nutritional signals, stress response and growth to ensure optimal fitness. The enigmatic introns of ribosomal proteins may prove to be a novel and vital link in this regulatory balancing act.

scholarly journals Cavin1 intrinsically disordered domains are essential for fuzzy electrostatic interactions and caveola formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikas A. Tillu ◽  
James Rae ◽  
Ya Gao ◽  
Nicholas Ariotti ◽  
Matthias Floetenmeyer ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Membrane Lipid ◽  
Membrane Curvature ◽  
Caveolin 1 ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Solution Generation ◽  
Endosomal System ◽  
Disordered Regions

AbstractCaveolae are spherically shaped nanodomains of the plasma membrane, generated by cooperative assembly of caveolin and cavin proteins. Cavins are cytosolic peripheral membrane proteins with negatively charged intrinsically disordered regions that flank positively charged α-helical regions. Here, we show that the three disordered domains of Cavin1 are essential for caveola formation and dynamic trafficking of caveolae. Electrostatic interactions between disordered regions and α-helical regions promote liquid-liquid phase separation behaviour of Cavin1 in vitro, assembly of Cavin1 oligomers in solution, generation of membrane curvature, association with caveolin-1, and Cavin1 recruitment to caveolae in cells. Removal of the first disordered region causes irreversible gel formation in vitro and results in aberrant caveola trafficking through the endosomal system. We propose a model for caveola assembly whereby fuzzy electrostatic interactions between Cavin1 and caveolin-1 proteins, combined with membrane lipid interactions, are required to generate membrane curvature and a metastable caveola coat.

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