RACK1 release from the Ribosome Couples Translational Regulation with Starving Signaling and Possibly Depends on Phosphorylation of Key Serine and Threonine Residues.

The balance between protein anabolism and catabolism sets the foundations on which cells build their homeostasis. RACK1 is a ribosome-associated scaffold protein involved in signal transduction. On the ribosome, RACK1 enhances specific translation.

FAM46C and FNDC3A Are Multiple Myeloma Tumor Suppressors That Act in Concert to Impair Clearing of Protein Aggregates and Autophagy.

Multiple myeloma is a plasma cell neoplasm characterized by the production of unfolded immunoglobulins, which cause endoplasmic reticulum (ER) stress and sensitivity to proteasome inhibition. The genomic landscape of multiple myeloma is characterized by the loss of several genes rarely mutated in other cancers that may underline specific weaknesses of multiple myeloma cells. One of these is that is lost in more than 10% of patients with multiple myeloma.

Ribosome profiling unveils translational regulation of metabolic enzymes in primary CD4 Th1 cells.

The transition from a naïve to an effector T cell is an essential event that requires metabolic reprogramming. We have recently demonstrated that the rapid metabolic changes that occur following stimulation of naïve T cells require the translation of preexisting mRNAs. Here, we provide evidence that translation regulates the metabolic asset of effector T cells.

Discovery and Preliminary Characterization of Translational Modulators that Impair the Binding of eIF6 to 60S Ribosomal Subunits.

Eukaryotic initiation factor 6 (eIF6) is necessary for the nucleolar biogenesis of 60S ribosomes. However, most of eIF6 resides in the cytoplasm, where it acts as an initiation factor. eIF6 is necessary for maximal protein synthesis downstream of growth factor stimulation.

Modulating eIF6 levels unveils the role of translation in ecdysone biosynthesis during Drosophila development.

During development, ribosome biogenesis and translation reach peak activities, due to impetuous cell proliferation. Current models predict that protein synthesis elevation is controlled by transcription factors and signalling pathways. Developmental models addressing translation factors overexpression effects are lacking.

Translating the Game: Ribosomes as Active Players.

Ribosomes have been long considered as executors of the translational program. The fact that ribosomes can control the translation of specific mRNAs or entire cellular programs is often neglected. Ribosomopathies, inherited diseases with mutations in ribosomal factors, show tissue specific defects and cancer predisposition.

RACK1 Specifically Regulates Translation through Its Binding to Ribosomes.

The translational capability of ribosomes deprived of specific nonfundamental ribosomal proteins may be altered. Physiological mechanisms are scanty, and it is unclear whether free ribosomal proteins can cross talk with the signaling machinery. RACK1 (receptor for activated C kinase 1) is a highly conserved scaffold protein, located on the 40S subunit near the mRNA exit channel.

The Translational Machinery of Human CD4 T Cells Is Poised for Activation and Controls the Switch from Quiescence to Metabolic Remodeling.

Naive T cells respond to T cell receptor (TCR) activation by leaving quiescence, remodeling metabolism, initiating expansion, and differentiating toward effector T cells. The molecular mechanisms coordinating the naive to effector transition are central to the functioning of the immune system, but remain elusive. Here, we discover that T cells fulfill this transitional process through translational control.

SBDS-Deficient Cells Have an Altered Homeostatic Equilibrium due to Translational Inefficiency Which Explains their Reduced Fitness and Provides a Logical Framework for Intervention.

Ribosomopathies are a family of inherited disorders caused by mutations in genes necessary for ribosomal function. Shwachman-Diamond Bodian Syndrome (SDS) is an autosomal recessive disease caused, in most patients, by mutations of the SBDS gene. SBDS is a protein required for the maturation of 60S ribosomes.

Direct and high throughput (HT) interactions on the ribosomal surface by iRIA.

Ribosomes function as platforms for binding of other molecules, but technologies for studying this process are lacking. Therefore we developed iRIA (in vitro Ribosomes Interaction Assay). In approach I, Artemia salina ribosomes spotted on solid phase are used for binding picomoles of analytes; in approach II, cellular extracts allow the measurement of ribosome activity in different conditions.

RACK1 depletion in a mouse model causes lethality, pigmentation deficits and reduction in protein synthesis efficiency.

The receptor for activated C-kinase 1 (RACK1) is a conserved structural protein of 40S ribosomes. Strikingly, deletion of RACK1 in yeast homolog Asc1 is not lethal. Mammalian RACK1 also interacts with many nonribosomal proteins, hinting at several extraribosomal functions.

Slimming down fat makes neuropathic hippo: the Fat/Hippo tumor suppressor pathway protects adult neurons through regulation of autophagy.

Polyglutamine diseases are accompanied by large-scale alterations of transcription that may be responsible for neurodegeneration. We have monitored early transcriptional alterations in a Drosophila model for dentatorubral-pallidoluysian atrophy (DRPLA) and reported the critical downregulation of the fat tumor suppressor gene. We show that, besides partially mediating neurodegeneration in the Drosophila model for DRPLA, fat and the downstream hippo pathway are essential for adult neuronal homeostasis.

Polyglutamine Atrophin provokes neurodegeneration in Drosophila by repressing fat.

Large alterations in transcription accompany neurodegeneration in polyglutamine (polyQ) diseases. These pathologies manifest both general polyQ toxicity and mutant protein-specific effects. In this study, we report that the fat tumour suppressor gene mediates neurodegeneration induced by the polyQ protein Atrophin.