P53-dependent hypusination of eIF5A affects mitochondrial translation and senescence immune surveillance.

Cellular senescence is characterized by a permanent growth arrest and is associated with tissue aging and cancer. Senescent cells secrete a number of different cytokines referred to as the senescence-associated secretory phenotype (SASP), which impacts the surrounding tissue and immune response. Here, we find that senescent cells exhibit higher rates of protein synthesis compared to proliferating cells and identify eIF5A as a crucial regulator of this process.

Breast Cancer Metastatic Progression Requires mRNA Posttranscriptional Suppression.

Cancer cell survival is highly dependent on its metabolic reprogramming, which supports not only cell growth but also confers to the tumor cells characteristics to initiate migration and colonization. Among the different mechanisms that are involved, translational control plays a significant role in oncogenesis; however, its impact on cancer progression still remains poorly understood. A study by Navickas and colleagues revealed that the RNA-binding protein heterogeneous nuclear ribonucleoprotein C (HNRNPC) functions as a translational regulator, and its downregulation in highly metastatic cells leads to the lengthening of 3' untranslated regions in HNRNPC-bound mRNAs, resulting in translational repression mediated by the AGO-miRNA RNA-induced silencing complex.

Context-Specific and Proximity-Dependent Labeling for the Proteomic Analysis of Spatiotemporally Defined Protein Complexes with Split-BioID.

Proximity-dependent labeling techniques such as BioID and APEX2 allow the biotinylation of proteins proximal to a protein of interest in living cells. Following streptavidin pulldown and mass spectrometry analysis, this enables the identification of native protein-protein interactions. Here we describe split-BioID, a protein-fragment complementation assay that increases the resolution of BioID.

4EHP-independent repression of endogenous mRNAs by the RNA-binding protein GIGYF2.

Initially identified as a factor involved in tyrosine kinase receptor signaling, Grb10-interacting GYF protein 2 (GIGYF2) has later been shown to interact with the 5' cap-binding protein 4EHP as part of a translation repression complex, and to mediate post-transcriptional repression of tethered reporter mRNAs. A current model proposes that GIGYF2 is indirectly recruited to mRNAs by specific RNA-binding proteins (RBPs) leading to translation repression through its association with 4EHP. Accordingly, we recently observed that GIGYF2 also interacts with the miRNA-induced silencing complex and probably modulates its translation repression activity.

Split-BioID a conditional proteomics approach to monitor the composition of spatiotemporally defined protein complexes.

Understanding the function of the thousands of cellular proteins is a central question in molecular cell biology. As proteins are typically part of multiple dynamic and often overlapping macromolecular complexes exerting distinct functions, the identification of protein-protein interactions (PPI) and their assignment to specific complexes is a crucial but challenging task. We present a protein fragments complementation assay integrated with the proximity-dependent biotinylation technique BioID.