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Gomes Neto, V.

Publications and source records attributed to Gomes Neto, V..

2 recordsLinked to original sources

Identification and functional characterization of novel murine DIS3L2 isoforms

RNases are key factors for the posttranscriptional control of gene expression due to their involvement in processing, degradation and quality control of all classes of RNA in eukaryotes. DIS3L2 is an evolutionarily conserved exoribonuclease involved in cytoplasmic RNA degradation pathways that regulate gene expression. Macrophages undergo great change in gene expression of specific genes that allow these cells to perform multiple functions in addition to defense against infection. Here, we analyzed the change in expression of macrophages genes in response to Leishmania major infection, and show evidence that the levels of RNases such as the RNA exosome, XRN1, and DIS3L2, are modulated by the infection. We then identified three DIS3L2 variants that are differentially expressed in murine macrophages and other cell lines. DIS3L2 isoforms show similar RNA binding affinity, but differences in exonucleolytic activity in in vitro assays. Furthermore, we characterized the interactome of the DIS3L2 variants, which shows similarities with respect to ribosomal proteins, but differences that hint at specific functions for each isoform. This work uncovers previously uncharacterized DIS3L2 isoforms that are active, whose functions have yet to be identified.

molecular biology↗

Phosphorylation patterns of pre-ribosomal proteins associated with the RNA exosome

The RNA exosome is an essential and ubiquitous RNase with exonucleolytic activity, involved in ribosome biogenesis and RNA quality control in eukaryotes. It is present both in nucleus and cytoplasm, and interacts with specific cofactors in each cell compartment, which are essential for recruitment and activity control of the exosome. Posttranslational modifications are known to regulate enzyme activity and protein interaction, although their precise roles are individually specific. In this study, we investigated the phosphorylation status of proteins associated with the nuclear (Rrp6) and core (Rrp46) subunits of the RNA exosome in Saccharomyces cerevisiae. Using co-immunoprecipitation followed by phosphopeptide enrichment and high-resolution mass spectrometry, we identified 121 phosphorylation sites on proteins functionally related to rRNA processing. Differential phosphorylation patterns between Rrp6 and Rrp46 co-immunoprecipitations are consistent with distinct exosome assemblies and suggest potential regulatory roles for phosphorylation. The results shown here highlight the role of phosphorylation in the recruitment and control of the exosome in RNA processing and degradation, offering new insights into the posttranscriptional control of gene expression.

molecular biology↗