Biology subjects

Weyn-Vanhentenryck, S. M.

Publications and source records attributed to Weyn-Vanhentenryck, S. M..

4 recordsLinked to original sources

bioRxiv2018

Modeling RNA-binding protein specificity in vivo by precisely registering protein-RNA crosslink sites

RNA-binding proteins (RBPs) regulate post-transcriptional gene expression by recognizing short and degenerate sequence elements in their target transcripts. Despite the expanding list of RBPs with in vivo binding sites mapped genomewide using crosslinking and immunoprecipitation (CLIP), defining precise RBP binding specificity remains challenging. We previously demonstrated that the exact protein-RNA crosslink sites can be mapped using CLIP data at single-nucleotide resolution and observed that crosslinking frequently occurs at specific positions in RBP motifs. Here we have developed a computational method, named mCross, to jointly model RBP binding specificity while precisely registering the crosslinking position in motif sites. We applied mCross to 112 RBPs using ENCODE eCLIP data and validated the reliability of the resulting motifs by genome-wide analysis of allelic binding sites also detected by CLIP. We found that the prototypical SR protein SRSF1 recognizes GGA clusters to regulate splicing in a much larger repertoire of transcripts than previously appreciated.

molecular biology↗

bioRxiv2018

Dazl regulates germ cell survival through a network of polyA proximal mRNA interactions

The RNA binding protein Dazl is essential for gametogenesis, but its direct in vivo functions, RNA targets, and the molecular basis for germ cell loss in DAZL null mice are unknown. Here, we mapped transcriptome-wide Dazl-RNA interactions in vivo, revealing Dazl binding to thousands of mRNAs via polyA-proximal 3UTR interactions. In parallel, fluorescence activated cell sorting and RNA-Seq identified mRNAs sensitive to Dazl deletion in male germ cells. Despite binding a broad set of mRNAs, integrative analyses indicate that Dazl post-transcriptionally controls only a subset of its mRNA targets, namely those corresponding to a network of genes critical for germ cell proliferation and survival. Additionally, we provide evidence that polyA sequences have key roles in specifying Dazl-RNA interactions across the transcriptome. Altogether, our results reveal a mechanism for Dazl-RNA binding, and illustrate that Dazl functions as a master regulator of a post-transcriptional mRNA program essential for germ cell survival.

molecular biology↗

bioRxiv2018

Precise temporal regulation of alternative splicing during neural development

Alternative splicing (AS) is a crucial step of gene expression that must be tightly controlled, but the precise timing of dynamic splicing switches during neural development and the underlying regulatory mechanisms are poorly understood. Here we systematically analyzed the temporal regulation of AS in a large number of transcriptome profiles of developing mouse cortices, in vivo purified neuronal subtypes, and neurons differentiated in vitro. Our analysis revealed early- and late-switch exons in genes with distinct functions, and these switches accurately define neuronal maturation stages. Integrative modeling suggests that these switches are under direct and combinatorial regulation by distinct sets of neuronal RNA-binding proteins including Nova, Rbfox, Mbnl and Ptbp. Surprisingly, various neuronal subtypes in the sensory systems lack Nova and/or Rbfox expression. These neurons retain the \"immature\" splicing program in early-switch exons, affecting numerous synaptic genes. These results provide new insights into the organization and regulation of the neurodevelopmental transcriptome.

molecular biology↗

bioRxiv2017

LIN28 selectively modulates a subclass of let-7 microRNAs

LIN28 is a bipartite RNA-binding protein that post-transcriptionally inhibits let-7 microRNAs to regulate development and influence disease states. However, the mechanisms of let-7 suppression remains poorly understood, because LIN28 recognition depends on coordinated targeting by both the zinc knuckle domain (ZKD)--which binds a GGAG-like element in the precursor--and the cold shock domain (CSD), whose binding sites have not been systematically characterized. By leveraging single-nucleotide-resolution mapping of LIN28 binding sites in vivo, we determined that the CSD recognizes a (U)GAU motif. This motif partitions the let-7 family into Class I precursors with both CSD and ZKD binding sites and Class II precursors with ZKD but no CSD binding sites. LIN28 in vivo recognition--and subsequent 3' uridylation and degradation--of Class I precursors is more efficient, leading to their stronger suppression in LIN28-activated cells and cancers. Thus, CSD binding sites amplify the effects of the LIN28 activation with potential implication in development and cancer.

molecular biology↗