<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth"^^ . "Ribosomes are evolutionary-conserved molecular machines consisting of the large 60S and\r\nthe small 40S subunits, which follow separate assembly routes but later function together as\r\nmature 80S ribosomes during translation. During ribosome biogenesis the pre-60S subunit\r\ngoes through many maturation steps that require numerous assembly factors. One of them,\r\nthe AAA+ ATPase Rea1 mediates two crucial remodelling steps in the nucleolus and the\r\nnucleoplasm, respectively, by binding via its MIDAS domain to the UBL domains of either Ytm1\r\n(WDR12 in humans) or Rsa4 (NLE1 in humans). These interactions, which are similar to a\r\ntypical integrin-ligand binding mechanism, are essential for cell growth, and their abolishment confers a lethal phenotype in yeast. Loss-of-function mutations of ribosomal proteins can lead to diseases called Ribosomopathies and growth factors and mitogenic stimuli can alter oncogenic signalling pathways by hyper-activating the tightly regulated ribosome biogenesis process, which, recently, has become a cancer therapy target. Therefore, analyzing the human ribosome assembly pathway might help find small chemical compounds impairing ribosome synthesis at specific maturation stages, which could be exploited for analytical and therapeutic purposes.\r\nDuring my PhD, I could reconstitute the interaction between human homologs of Rea1-MIDAS\r\nand Rsa4-UBL domains in vitro and crystallize this heterodimer. Using a dominant-negative\r\nrsa4 mutant, mapping the amino acid 85 of the UBL domain, I could impair this interaction,\r\nwhich allowed me to evaluate the effects of the loss of Rea1-MIDAS-Rsa4-UBL binding in vitro\r\nand human culture cells. I successfully crystallized the complex, obtaining the atomic model of the MIDAS-UBL interaction, a central finding supporting the search for small chemical\r\ncompounds impairing the human Rea1-MIDAS-Rsa4-UBL interaction. Eventually, we could\r\nfind one inhibitor, which I tested in vitro and human cancer cells. In addition, using the\r\ndominant-negative phenotype generated by the rsa4-UBL mutant in human cells, we\r\nsuccessfully isolated a human pre-60S ribosomal particle and visualized it by cryo-electron\r\nmicroscopy.\r\nThus, my thesis provided structural and functional insights into the Rea1-MIDAS–Rsa4-UBL\r\ninteraction in the human system, confirming its importance for human pre-60S ribosome\r\nassembly and cell viability. These findings may allow further optimization of small chemical\r\ncompounds to efficiently inhibit human ribosome biogenesis in cancer cells, alone or in\r\ncombination with other known cancer drugs."^^ . "2024" . . . . . . . "Federica"^^ . "Fiorentino"^^ . "Federica Fiorentino"^^ . . . . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (PDF)"^^ . . . "Federica thesis 19-10-2022.pdf"^^ . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Structural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #33129 \n\nStructural and biochemical analysis of the human Rea1-Rsa4 pre-ribosomal complex enables the identification of small molecule inhibitors that impair human cancer cell growth\n\n" . "text/html" . .