Biology subjects

Avolio, R.

Publications and source records attributed to Avolio, R..

5 recordsLinked to original sources

bioRxiv2025

The molecular chaperone TRAP1 promotes translation of Luc7l3 mRNA to enhance ovarian cancer cell proliferation

Heat shock proteins have been increasingly identified in RNA-interactomes, suggesting potential roles beyond their canonical functions. Among those, the cancer-linked chaperone TRAP1 has been mainly characterized for its regulatory role on respiratory complex activity and protein synthesis, while its specific function as an RNA-binding protein (RBP) remains unclear. In this study, we confirmed the RNA-binding activity of TRAP1 in living cells using both protein- and RNA-centric approaches and demonstrated that multiple TRAP1 regions cooperate in such binding. Enhanced cross-linking and immunoprecipitation (eCLIP) in high-grade serous ovarian cancer cells revealed that TRAP1 primarily binds cytosolic protein-coding genes, with the majority coding for splicing-related factors. Notably, among TRAP1 most significantly bound transcripts, we identified the splicing factor LUC7L3, a U1 snRNP component involved in cell proliferation. We confirmed TRAP1 binding to Luc7l3 transcript by RIP-qPCR and showed that TRAP1 promotes Luc7l3 mRNA translation. Furthermore, we demonstrated that TRAP1 enhances ovarian cancer cell proliferation through LUC7L3 translational regulation. In summary, our findings provide the first comprehensive characterization of TRAP1 as an RBP and identify a critical target for ovarian cancer cell proliferation, offering new insights into its multifaceted roles in tumor biology.

cancer biology↗

bioRxiv2025

Novel ciliary protein TRIM8 is a multifunctional workhorse during mitosis

TRIM8 is an E3 ubiquitin ligase that functions as both a tumour suppressor and an oncoprotein. Earlier, we reported that TRIM8 interacts with key regulators of mitotic spindle assembly, and that TRIM8 knockdown results in mitotic delay and aneuploidy. In this study, we implemented a multi-omics strategy with differential transcriptomic (single-cell RNA sequencing or scRNA-seq), translatomic (polysome profiling with RNA-seq), and proteomic (LC-MS/MS) approaches to elucidate the involvement of TRIM8 in different levels (transcription, translation, post-translation) and stages (G0/G1, S, G2/M) of mitotic cell cycle regulation and progression. With the aid of differential transcriptomic (scRNA-seq) and proteomic (LC-MS/MS) approaches, we show that depletion of TRIM8 perturbs the canonical "Cell Cycle Control of Chromosomal Replication" pathway and demonstrate that TRIM8 negatively regulates the expression of TOP2A, known to be essential for genomic integrity. We also show that TRIM8 downregulation induces substantial alterations in the translation activity of cells and results in the upregulation of polysome-bound MALAT1 lncRNA by means of significant changes in polysome profiling coupled with RNA-sequencing. Moreover, we unveil endogenous TRIM8 as a novel ciliary protein that co-localizes with CEP170, required for ciliary function, in the centrosomal region throughout all mitotic phases. Our work shows the dynamic role played by a TRIM family protein across various stages of mitosis for the first time, laying the foundation for exploring the therapeutic potential of TRIM8 in addressing cell cycle-related diseases, including cancer. HIGHLIGHTSO_LITRIM8 is involved in transcriptional and post-translational regulation of "Cell Cycle Control of Chromosomal Replication" pathway and oversees the expression of TOP2A, essential for mitotic chromosome structure maintenance. C_LIO_LIThe silencing of TRIM8 induces changes in cellular translation activity and alters the expression pattern of key translational proteins. Additionally, TRIM8-silencing leads to an elevation of long non-coding RNA (lncRNA) MALAT1 in the polysome-bound fraction. C_LIO_LITRIM8 is identified as a novel ciliary protein. C_LIO_LISilencing of TRIM8 results in the upregulation of the centrosomal protein CEP170, and both proteins co-localize in the centrosomal region throughout all stages of mitosis. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/646005v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1b03f1borg.highwire.dtl.DTLVardef@1ff16e4org.highwire.dtl.DTLVardef@37f07borg.highwire.dtl.DTLVardef@8d28af_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2023

Cytosolic and mitochondrial translation elongation are coordinated through the molecular chaperone TRAP1 for the synthesis and import of mitochondrial proteins

A complex interplay between mRNA translation and cellular respiration has been recently unveiled, but its regulation in humans is poorly characterized in either health or disease. Cancer cells radically reshape both biosynthetic and bioenergetic pathways to sustain their aberrant growth rates. In this regard, we have shown that the molecular chaperone TRAP1 not only regulates the activity of respiratory complexes, behaving alternatively as an oncogene or a tumor suppressor, but also plays a concomitant moonlighting function in mRNA translation regulation. Herein we identify the molecular mechanisms involved, demonstrating that TRAP1: i) binds both mitochondrial and cytosolic ribosomes as well as translation elongation factors, ii) slows down translation elongation rate, and iii) favors localized translation in the proximity of mitochondria. We also provide evidence that TRAP1 is coexpressed in human tissues with the mitochondrial translational machinery, which is responsible for the synthesis of respiratory complex proteins. Altogether, our results show an unprecedented level of complexity in the regulation of cancer cell metabolism, strongly suggesting the existence of a tight feedback loop between protein synthesis and energy metabolism, based on the demonstration that a single molecular chaperone plays a role in both mitochondrial and cytosolic translation, as well as in mitochondrial respiration.

biochemistry↗

bioRxiv2020

Coordinated post-transcriptional control of oncogene-induced senescence by UNR/CSDE1

Oncogene-induced senescence (OIS) is a form of stable cell cycle arrest elicited in cells as a response to oncogenic stimulation. OIS must be bypassed for transformation, but the mechanisms of OIS establishment and bypass remain poorly understood, especially at the post-transcriptional level. Here we show that the RNA binding protein UNR/CSDE1, previously involved in melanoma metastasis, unexpectedly enables OIS in primary mouse keratinocytes that have been challenged by over-expression of oncogenic H-Ras. Depletion of CSDE1 leads to senescence bypass, cell immortalization and tumor formation in vivo, indicating that CSDE1 behaves as a tumor suppressor. Using iCLIP-Seq, RNA-Seq and polysome profiling we have uncovered two independent molecular branches by which CSDE1 contributes to OIS. On one hand, CSDE1 enhances the senescence-associated secretory phenotype (SASP) by promoting the stability of SASP factor mRNAs. On the other hand, CSDE1 represses the synthesis of the pro-oncogenic RNA binding protein YBX1. Importantly, depletion of YBX1 from immortal keratinocytes rescues senescence and uncouples proliferation arrest from the SASP, revealing multilayered post-transcriptional mechanisms exerted by CSDE1 to control senescence. Our data uncover a novel function of CSDE1, and highlight the relevance of post-transcriptional control in the regulation of senescence.

molecular biology↗

bioRxiv2018

Understanding RNP remodelling uncovers RBPs functionally required for viral replication

The compendium of RNA-binding proteins (RBPome) has been greatly expanded by the development of RNA-interactome capture (RNA-IC). However, it remains unknown how responsive is the RBPome and whether these responses are biologically relevant. To answer these questions, we created comparative RNA-IC to analyse cells challenged with an RNA virus, called sindbis (SINV). Strikingly, the virus altered the activity of 245 RBPs, many of which were newly discovered by RNA-IC. Mechanistically, alterations in RNA binding upon SINV infection are caused by changes in the subcellular localisation of RBPs and RNA availability. Moreover, RBPome responses are crucial, as perturbation of dynamic RBPs modulates the capacity of the virus to infect the cell. For example, ablation of XRN1 causes cells to be refractory to infection, while GEMIN5 moonlights as a novel antiviral factor. Therefore, RBPome remodelling provides a mechanism by which cells can extensively rewire gene expression in response to physiological cues.\n\nHIGHLIGHTSO_LIA quarter of the RBPome remodels upon SINV infection.\nC_LIO_LIThe remodelling is caused by changes in protein localisation and RNA availability.\nC_LIO_LIRewiring of the RBPome is crucial for viral infection efficacy.\nC_LIO_LIWe discover RBPs with previously unknown anti- or pro-viral activity.\nC_LI

molecular biology↗