Project description:Cell fate transitions involve rapid changes of gene expression patterns and global chromatin remodeling, yet the underlying regulatory pathways remain incompletely understood. Here, we used transcription-factor induced reprogramming of somatic cells into pluripotent cells to screen for novel regulators of cell fate change. We identified the RNA processing factor Nudt21, a component of the pre-mRNA cleavage and polyadenylation complex, as a potent barrier to reprogramming. Importantly, suppression of Nudt21 not only enhanced the generation of induced pluripotent stem cells but also facilitated the conversion of fibroblasts into trophoblast stem cells and delayed the differentiation of myeloid precursor cells into macrophages, suggesting a broader role for Nudt21 in restricting cell fate change. Polyadenylation site sequencing (PAS-seq) revealed that Nudt21 directs differential polyadenylation of over 1,500 transcripts in cells acquiring pluripotency. While only a fraction of these transcripts changed expression at the protein level, this fraction was strongly enriched for chromatin regulators, including components of the PAF, polycomb, and trithorax complexes. Co-suppression analysis further suggests that these chromatin factors are largely responsible for Nudt21’s effect on reprogramming, providing a mechanistic basis for our observations. Collectively, our data uncover Nudt21 as a novel post-transcriptional regulator of mammalian cell fate and establish a direct, previously unappreciated link between alternative polyadenylation and chromatin signaling.
Project description:Cell fate transitions involve rapid changes of gene expression patterns and global chromatin remodeling, yet the underlying regulatory pathways remain incompletely understood. Here, we used transcription-factor induced reprogramming of somatic cells into pluripotent cells to screen for novel regulators of cell fate change. We identified the RNA processing factor Nudt21, a component of the pre-mRNA cleavage and polyadenylation complex, as a potent barrier to reprogramming. Importantly, suppression of Nudt21 not only enhanced the generation of induced pluripotent stem cells but also facilitated the conversion of fibroblasts into trophoblast stem cells and delayed the differentiation of myeloid precursor cells into macrophages, suggesting a broader role for Nudt21 in restricting cell fate change. Polyadenylation site sequencing (PAS-seq) revealed that Nudt21 directs differential polyadenylation of over 1,500 transcripts in cells acquiring pluripotency. While only a fraction of these transcripts changed expression at the protein level, this fraction was strongly enriched for chromatin regulators, including components of the PAF, polycomb, and trithorax complexes. Co-suppression analysis further suggests that these chromatin factors are largely responsible for Nudt21’s effect on reprogramming, providing a mechanistic basis for our observations. Collectively, our data uncover Nudt21 as a novel post-transcriptional regulator of mammalian cell fate and establish a direct, previously unappreciated link between alternative polyadenylation and chromatin signaling.
Project description:Cell fate transitions involve rapid changes of gene expression patterns and global chromatin remodeling, yet the underlying regulatory pathways remain incompletely understood. Here, we used transcription-factor induced reprogramming of somatic cells into pluripotent cells to screen for novel regulators of cell fate change. We identified the RNA processing factor Nudt21, a component of the pre-mRNA cleavage and polyadenylation complex, as a potent barrier to reprogramming. Importantly, suppression of Nudt21 not only enhanced the generation of induced pluripotent stem cells but also facilitated the conversion of fibroblasts into trophoblast stem cells and delayed the differentiation of myeloid precursor cells into macrophages, suggesting a broader role for Nudt21 in controlling cell fate change. Polyadenylation site sequencing (PAS-seq) revealed that Nudt21 directs differential polyadenylation of over 1,500 transcripts in cells acquiring pluripotency. While only a fraction of these transcripts changed expression at the protein level, this fraction was strongly enriched for chromatin regulators, including components of the PAF, Polycomb, and Trithorax complexes. Co-suppression analysis further suggests that these chromatin factors are potent mediators of reprogramming, providing a mechanistic basis for our observations. Collectively, our data uncover Nudt21 as a novel post-transcriptional regulator of mammalian cell fate and establish a direct, previously unappreciated link between alternative polyadenylation and chromatin signaling.
Project description:HCC is the third leading cause of cancer-related deaths worldwide. However, the molecular mechanisms underlying the progression of HCC is still largely elusive. NUDT21 (CFIm25) is an important mediator of 3′ UTR APA and demonstrates a causal relationship between alternative polyadenylation and cancer cell proliferation. Although the function of NUDT21 has been explored in glioblastoma tumor, the functional significance of NUDT21 in solid tumors is not well understood. In this study, we observed that NUDT21 is suppressed in human HCC tissues, compared to adjacent noncancerous tissues. In addition we found that the HCC patients with suppressed NUDT21 are statistically associated with poor outcomes. These observations suggest NUDT21 possibly functions as tumor suppressor in hepatocellular carcinoma (HCC).
Project description:We previously showed that NUDT21-spanning copy-number variations (CNVs) are associated with intellectual disability (ID), and that NUDT21-encoded CFIm25 regulates the protein levels of at least one dose-sensitive, ID-associated protein: MeCP2 (Gennarino et al., 2015). However, the patients’ CNVs also spanned multiple other genes raising the possibility that loss or gain of these other genes caused their symptoms. To determine if reduced NUDT21 function alone is sufficient to cause disease, we generated Nudt21 heterozygous null mice to mimic the human state of reduced expression. We found that although these mice have 50% reduced Nudt21 mRNA, they only have 30% less of its cognate protein, CFIm25. Despite this partial protein-level compensation, the Nudt21+/- mice have learning deficits and cortical hyperexcitability. Further, to determine the molecular mechanism driving neural dysfunction, we partially inhibited NUDT21 in human embryonic stem cell-derived neurons to reduce CFIm25 by 30%. This reduction in CFIm25 was sufficient to induce misregulated alternative polyadenylation (APA) and protein levels in hundreds of genes, dozens of which are associated with intellectual disability and whose dysregulation is likely contributing to disease symptoms. Altogether, these results indicate that disruption of NUDT21-regulated APA events in the brain can cause intellectual disability.
Project description:The only S-adenosymethionine (SAM) synthetase expressed in most human cells, MAT2A, is regulated by intron detention. Using a GFP fusion reporter, we conducted a CRISPR screen to identify regulators of this alternative splicing event. The screen identified METTL16, a known regulator of this process, and NUDT21. NUDT21 encodes the CFIm25 protein a member of the CFIm complex involved in alternative polyadenylation. Validation and follow-up studies support the idea that CFIm25 and the larger CFIm complex plays an unanticipated role in splicing of the MAT2A detained intron.
Project description:Alternative polyadenylation modulates gene expresion via changing the length of 3'UTR. Among the complexes involving in APA, CFIm complex plays a central role in determining the usage of proximal PAS versus distal one. NUDT21, also named as CFIm25 and CPSF5, is the core component of CFIm complex. To date, except CPSF6 and CPSF7, there are few proteins reported to interact with NUDT21. In this project, the interactome of NUDT21 was identified by IP-MS.
Project description:We previously showed that NUDT21-spanning copy-number variations (CNVs) are associated with intellectual disability (ID), and that NUDT21-encoded CFIm25 regulates the protein levels of at least one dose-sensitive, ID-associated protein: MeCP2 (Gennarino et al., 2015). However, the patients’ CNVs also spanned multiple other genes raising the possibility that loss or gain of these other genes caused their symptoms. To determine if reduced NUDT21 function alone is sufficient to cause disease, we generated Nudt21 heterozygous null mice to mimic the human state of reduced expression. We found that although these mice have 50% reduced Nudt21 mRNA, they only have 30% less of its cognate protein, CFIm25. Despite this partial protein-level compensation, the Nudt21+/- mice have learning deficits and cortical hyperexcitability. Further, to determine the molecular mechanism driving neural dysfunction, we partially inhibited NUDT21 in human embryonic stem cell-derived neurons to reduce CFIm25 by 30%. This reduction in CFIm25 was sufficient to induce misregulated alternative polyadenylation (APA) and protein levels in hundreds of genes, dozens of which are associated with intellectual disability and whose dysregulation is likely contributing to disease symptoms. Altogether, these results indicate that disruption of NUDT21-regulated APA events in the brain can cause intellectual disability.
Project description:We previously showed that NUDT21-spanning copy-number variations (CNVs) are associated with intellectual disability (ID), and that NUDT21-encoded CFIm25 regulates the protein levels of at least one dose-sensitive, ID-associated protein: MeCP2 (Gennarino et al., 2015). However, the patients’ CNVs also spanned multiple other genes raising the possibility that loss or gain of these other genes caused their symptoms. To determine if reduced NUDT21 function alone is sufficient to cause disease, we generated Nudt21 heterozygous null mice to mimic the human state of reduced expression. We found that although these mice have 50% reduced Nudt21 mRNA, they only have 30% less of its cognate protein, CFIm25. Despite this partial protein-level compensation, the Nudt21+/- mice have learning deficits and cortical hyperexcitability. Further, to determine the molecular mechanism driving neural dysfunction, we partially inhibited NUDT21 in human embryonic stem cell-derived neurons to reduce CFIm25 by 30%. This reduction in CFIm25 was sufficient to induce misregulated alternative polyadenylation (APA) and protein levels in hundreds of genes, dozens of which are associated with intellectual disability and whose dysregulation is likely contributing to disease symptoms. Altogether, these results indicate that disruption of NUDT21-regulated APA events in the brain can cause intellectual disability.