Project description:The synthesis and decay of mRNA in cells are carried out by influencing each other, and their balance is altered by either external or internal cues, resulting in changes in the dynamics of the cell. We have previously reported that it is indispensable that an array of mRNAs which shape a phenotype should be degraded before cellular transitions, such as cellular reprogramming and differentiation. In adipogenesis, the interaction between DDX6 and 4E-T had a definitive impact on the pathway in the processing body (PB). We screened a library of α-helix analog with an alkaloid backbone to determine a compound inhibiting the binding between DDX6 and 4E-T proteins, because the interaction is executed between α-helix of structured and internally disordered protein, respectively, and identified IAMC-00192 as a lead compound. The compound showed a direct inhibition in the interaction between DDX6 and 4E-T by using WAVE system with a KD of 774.3 nM. The compound inhibited PB formation that temporally increases during adipogenesis and epithelial-mesenchymal transition (EMT), and significantly suppressed their cellular transition. We also found that in the EMT model, the half-life of pre-existing mRNAs in PBs was extended twofold by the compound. The novel inhibitor of RNA decay will be not only a tool to analyze in detail what pathological conditions RNA decay affects and how it regulates the state, but also lead to drug discovery of the first in class as RNA decay inhibitor.
Project description:MicroRNA (miRNA) abundance is tightly controlled by regulation of biogenesis and decay. Here, we show that the mir-35 miRNA family undergoes selective decay at the transition from embryonic to larval development in C. elegans. The seed sequence of the miRNA is necessary and largely sufficient for this regulation. Sequences outside the seed (3' end) regulate mir-35 abundance in the embryo but are not necessary for sharp decay at the transition to larval development. Enzymatic modifications of the miRNA 3' end are neither prevalent nor correlated with changes in decay, suggesting that miRNA 3' end display is not a core feature of this mechanism and further supporting a seed-driven decay model. Our findings demonstrate that seed-sequence-specific decay can selectively and coherently regulate all redundant members of a miRNA seed family, a class of mechanism that has great biological and therapeutic potential for dynamic regulation of a miRNA family's target repertoire.
Project description:The naïve pluripotent epiblast cells become polarized into a rosette-like structure, followed by irreversible transition into primed pluripotency during one of the fastest morphological switches termed lumenogenesis. This requires rapid decay of pluripotency-associated mRNAs, but the underlying mechanism remains unknown. Guided by machine learning and metabolic RNA sequencing, we identified RNA binding proteins (RBPs), especially LIN28A, as primary mRNA decay factors. To understand if RBP dynamics steer embryogenesis, we used mRNA-RBP interactome capture during naïve-rosette-epiblast-gastrulation progression. We identified a dramatic increase in LIN28A mRNA binding, driven by its nucleolus-to-cytoplasm translocation during the naïve-primed pluripotency transition. Cytoplasmic LIN28A binds to 3’UTRs of pluripotency-associated mRNAs to directly stimulate their decay, and thereby progression to lumenogenesis. Accordingly, forced nuclear retention of LIN28A impeded lumenogenesis, causing an unforeseen embryonic multiplication and impaired gastrulation. This reveals selective mRNA decay, driven by nucleo-cytoplasmic RBP translocation, as an intrinsic mechanism for cell identity switch that controls embryonic timing of lumenogenesis.
Project description:The naïve pluripotent epiblast cells become polarized into a rosette-like structure, followed by irreversible transition into primed pluripotency during one of the fastest morphological switches termed lumenogenesis. This requires rapid decay of pluripotency-associated mRNAs, but the underlying mechanism remains unknown. Guided by machine learning and metabolic RNA sequencing, we identified RNA binding proteins (RBPs), especially LIN28A, as primary mRNA decay factors. To understand if RBP dynamics steer embryogenesis, we used mRNA-RBP interactome capture during naïve-rosette-epiblast-gastrulation progression. We identified a dramatic increase in LIN28A mRNA binding, driven by its nucleolus-to-cytoplasm translocation during the naïve-primed pluripotency transition. Cytoplasmic LIN28A binds to 3’UTRs of pluripotency-associated mRNAs to directly stimulate their decay, and thereby progression to lumenogenesis. Accordingly, forced nuclear retention of LIN28A impeded lumenogenesis, causing an unforeseen embryonic multiplication and impaired gastrulation. This reveals selective mRNA decay, driven by nucleo-cytoplasmic RBP translocation, as an intrinsic mechanism for cell identity switch that controls embryonic timing of lumenogenesis.
Project description:Pumilio (PUM) is a Drosophila member of a conserved family of sequence-specific RNA-binding proteins that have been shown to regulate mRNA stability and/or translation in a variety of organisms. PUM has been shown to repress the translation of several mRNAs in the Drosophila early embryo; failure to repress these targets leads to lethal developmental defects. Here we use a combination of microarray-based gene expression profiling and next-generation sequencing to identify more than 200 mRNAs that are associated with full-length PUM protein in early embryos and to define a global role for PUM in mRNA decay. Surprisingly, despite the fact that PUM is maternally supplied and thus is present from the beginning of embryogenesis, the vast majority of PUM-directed decay occurs only after zygotic genome activation. We show that the smaug mRNA, which itself encodes an RNA-binding protein that directs transcript decay, is a direct target of PUM via binding sites in the smg 3'UTR. Whereas the endogenous smaug mRNA and the transgenic reporter mRNA that carries the smaug 3'UTR undergo decay after zygotic genome activation, a reporter with an array of PUM-binding sites decays before zygotic genome activation. These data support a model in which additional cis-elements in the smg 3'UTR delay decay until after zygotic genome activation.
Project description:The naïve pluripotent epiblast cells become polarized into a rosette-like structure, followed by irreversible transition into primed pluripotency during one of the fastest morphological switches termed lumenogenesis. This requires rapid decay of pluripotency-associated mRNAs, but the underlying mechanism remains unknown. Guided by machine learning and metabolic RNA sequencing, we identified RNA binding proteins (RBPs), especially LIN28A, as primary mRNA decay factors. To understand if RBP dynamics steer embryogenesis, we used mRNA-RBP interactome capture during naïve-rosette-epiblast-gastrulation progression. We identified a dramatic increase in LIN28A mRNA binding, driven by its nucleolus-to-cytoplasm translocation during the naïve-primed pluripotency transition. Cytoplasmic LIN28A binds to 3’UTRs of pluripotency-associated mRNAs to directly stimulate their decay, and thereby progression to lumenogenesis. Accordingly, forced nuclear retention of LIN28A impeded lumenogenesis, causing an unforeseen embryonic multiplication and impaired gastrulation. This reveals selective mRNA decay, driven by nucleo-cytoplasmic RBP translocation, as an intrinsic mechanism for cell identity switch that controls embryonic timing of lumenogenesis.
Project description:The naïve pluripotent epiblast cells become polarized into a rosette-like structure, followed by irreversible transition into primed pluripotency during one of the fastest morphological switches termed lumenogenesis. This requires rapid decay of pluripotency-associated mRNAs, but the underlying mechanism remains unknown. Guided by machine learning and metabolic RNA sequencing, we identified RNA binding proteins (RBPs), especially LIN28A, as primary mRNA decay factors. To understand if RBP dynamics steer embryogenesis, we used mRNA-RBP interactome capture during naïve-rosette-epiblast-gastrulation progression. We identified a dramatic increase in LIN28A mRNA binding, driven by its nucleolus-to-cytoplasm translocation during the naïve-primed pluripotency transition. Cytoplasmic LIN28A binds to 3’UTRs of pluripotency-associated mRNAs to directly stimulate their decay, and thereby progression to lumenogenesis. Accordingly, forced nuclear retention of LIN28A impeded lumenogenesis, causing an unforeseen embryonic multiplication and impaired gastrulation. This reveals selective mRNA decay, driven by nucleo-cytoplasmic RBP translocation, as an intrinsic mechanism for cell identity switch that controls embryonic timing of lumenogenesis.
Project description:The naïve pluripotent epiblast cells become polarized into a rosette-like structure, followed by irreversible transition into primed pluripotency during one of the fastest morphological switches termed lumenogenesis. This requires rapid decay of pluripotency-associated mRNAs, but the underlying mechanism remains unknown. Guided by machine learning and metabolic RNA sequencing, we identified RNA binding proteins (RBPs), especially LIN28A, as primary mRNA decay factors. To understand if RBP dynamics steer embryogenesis, we used mRNA-RBP interactome capture during naïve-rosette-epiblast-gastrulation progression. We identified a dramatic increase in LIN28A mRNA binding, driven by its nucleolus-to-cytoplasm translocation during the naïve-primed pluripotency transition. Cytoplasmic LIN28A binds to 3’UTRs of pluripotency-associated mRNAs to directly stimulate their decay, and thereby progression to lumenogenesis. Accordingly, forced nuclear retention of LIN28A impeded lumenogenesis, causing an unforeseen embryonic multiplication and impaired gastrulation. This reveals selective mRNA decay, driven by nucleo-cytoplasmic RBP translocation, as an intrinsic mechanism for cell identity switch that controls embryonic timing of lumenogenesis.