LIN28A-mediated regulation of microRNA biogenesis in mouse embryonic stem cell (A3-1) [Agilent]
Ontology highlight
ABSTRACT: LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, LIN28A was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28 preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells.
Project description:LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, Lin28 was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28A preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells. Examination of RNA binding of LIN28A and translation in mouse embryonic stem cell.
Project description:LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, LIN28A was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28 preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells. Examination of miRNA level in embryonic stem cell treated with siRNA for GFP or for Lin28a
Project description:LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, LIN28A was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28 preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells. Examination of mRNA level in embryonic stem cell treated with siRNA for GFP or for Lin28a
Project description:LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, Lin28 was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28A preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells.
Project description:LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, LIN28A was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28 preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells.
Project description:The RNA-binding protein LIN28A is required for maintaining tissue homeostasis, including in the reproductive system, but the underlying mechanisms on how LIN28A regulates germline progenitors remain unclear. Here, we dissected LIN28A-binding targets using high-throughput sequencing of RNAs isolated by crosslinking immunoprecipitation (HITS-CLIP) in the mouse testes. LIN28A preferentially binds to mRNA coding sequence (CDS) or 3'UTR regions at sites enriched wiGAG(A) sequences. Further investigation of Lin28a null mouse testes indicated that meiosis-associated mRNAs bound by LIN28A were differentially expressed. Next, ribosome profiling revealed that the mRNA levels of these targets were significantly reduced in polysome fractions, and their protein expression levels decreased in the Lin28a null mouse testes, even when meiotic arrest in the null mouse testes was not apparent. Collectively, these findings provide a set of LIN28A-regulated target mRNAs, and show that LIN28A binding might be mechanism through which LIN28A acts to regulate undifferentiated spermatogonia fates and male fertility in mammals.
Project description:During the early stages of embryonic development, Lin28a is expressed at high levels and gradually decreases as the embryo develops. As an RNA-binding protein, Lin28a maintains a subset of adult muscle stem cells (MuSCs) in an embryonic-like state. However, the specific mechanism for regulating RNA metabolism is not yet clear. Through the analysis of Lin28a-associated genes, we have revealed that Lin28a promotes the expression of Igf2bp3 and interacts with the Igf2bp3 protein, controlling the proliferation of MuSCs. In response to stress stimuli, Lin28a rapidly upregulates the expression of Igf2bp3, recruits mRNAs by interacting with the N6-methyladenosine (m6A) reader Igf2bp3, and forms protein complexes with G3bp1 in stress granules. Sequencing of the transcriptome and RNAs immunoprecipitated by Lin28a, Igf2bp3, and m6A antibodies in Lin28a+ MuSCs further revealed that Lin28a and Igf2bp3 collaboratively regulate the expression of DNA repair-related genes such as Fancm and Usp1 to promote DNA repair after oxidative stress. Therefore, Lin28a regulates the expression of DNA damage repair-related genes and upregulates the DNA stress response of MuSCs through stress granule regulation of m6A-modified mRNAs. This positive regulation contributes to the self-renewal of MuSCs.
Project description:Lin28, a well-known RNA-binding protein, regulates diverse cellular properties. All physiological functions of Lin28A characterized so far have been attributed to its repression of let-7 miRNA biogenesis or modulation of the mRNA translational efficiency. Here we show that Lin28A directly binds to a consensus DNA sequence in vitro and in mouse embryonic stem cells in vivo. ChIP-seq and RNA-seq reveal the enrichment of Lin28A binding around transcription start sites, and a positive correlation between its genomic occupancy and expression of many associated genes. Mechanistically, Lin28A recruits 5-methylcytosine-dioxygenase Tet1 to genomic binding sites to orchestrate 5-methylcytosine and 5-hydroxymethylcytosine dynamics. Either Lin28A or Tet1 knockdown leads to dysregulated DNA methylation and expression of common target genes. These results reveal a surprising role for Lin28A in transcriptional regulation via epigenetic DNA modifications and provide a new framework for understanding mechanisms underlying versatile functions of Lin28A in mammalian systems. Examine the DNA binding ability of Lin28 and its roles in regulating gene expression by coordinating with Tet1
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.