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Full-Text Articles in Life Sciences
A Conserved Three-Nucleotide Core Motif Defines Musashi Rna Binding Specificity, Nancy Zearfoss, Laura Deveau, Carina Clingman, Eric Schmidt, Emily Johnson, Francesca Massi, Sean Ryder
A Conserved Three-Nucleotide Core Motif Defines Musashi Rna Binding Specificity, Nancy Zearfoss, Laura Deveau, Carina Clingman, Eric Schmidt, Emily Johnson, Francesca Massi, Sean Ryder
Sean P. Ryder
Musashi (MSI) family proteins control cell proliferation and differentiation in many biological systems. They are overexpressed in tumors of several origins, and their expression level correlates with poor prognosis. MSI proteins control gene expression by binding RNA and regulating its translation. They contain two RNA recognition motif (RRM) domains, which recognize a defined sequence element. The relative contribution of each nucleotide to the binding affinity and specificity is unknown. We analyzed the binding specificity of three MSI family RRM domains using a quantitative fluorescence anisotropy assay. We found that the core element driving recognition is the sequence UAG. Nucleotides outside …
Quaking Regulates Hnrnpa1 Expression Through Its 3' Utr In Oligodendrocyte Precursor Cells, Nancy Zearfoss, Carina Clingman, Brian Farley, Lisa Mccoig, Sean Ryder
Quaking Regulates Hnrnpa1 Expression Through Its 3' Utr In Oligodendrocyte Precursor Cells, Nancy Zearfoss, Carina Clingman, Brian Farley, Lisa Mccoig, Sean Ryder
Sean P. Ryder
In mice, Quaking (Qk) is required for myelin formation; in humans, it has been associated with psychiatric disease. QK regulates the stability, subcellular localization, and alternative splicing of several myelin-related transcripts, yet little is known about how QK governs these activities. Here, we show that QK enhances Hnrnpa1 mRNA stability by binding a conserved 3' UTR sequence with high affinity and specificity. A single nucleotide mutation in the binding site eliminates QK-dependent regulation, as does reduction of QK by RNAi. Analysis of exon expression across the transcriptome reveals that QK and hnRNP A1 regulate an overlapping subset of transcripts. Thus, …
Rna Target Specificity Of The Embryonic Cell Fate Determinant Pos-1, Brian Farley, John Pagano, Sean Ryder
Rna Target Specificity Of The Embryonic Cell Fate Determinant Pos-1, Brian Farley, John Pagano, Sean Ryder
Sean P. Ryder
Specification of Caenorhabditis elegans body axes and cell fates occurs prior to the activation of zygotic transcription. Several CCCH-type tandem zinc finger (TZF) proteins coordinate local activation of quiescent maternal mRNAs after fertilization, leading to asymmetric expression of factors required for patterning. The primary determinant of posterior fate is the TZF protein POS-1. Mutants of pos-1 are maternal effect lethal with a terminal phenotype that includes excess pharyngeal tissue and no endoderm or germline. Here, we delineate the consensus POS-1 recognition element (PRE) required for specific recognition of its target mRNAs. The PRE is necessary but not sufficient to pattern …
Argonaute Protein Identity And Pairing Geometry Determine Cooperativity In Mammalian Rna Silencing, Jennifer Broderick, William Salomon, Sean Ryder, Neil Aronin, Phillip Zamore
Argonaute Protein Identity And Pairing Geometry Determine Cooperativity In Mammalian Rna Silencing, Jennifer Broderick, William Salomon, Sean Ryder, Neil Aronin, Phillip Zamore
Sean P. Ryder
Small RNAs loaded into Argonaute proteins direct silencing of complementary target mRNAs. It has been proposed that multiple, imperfectly complementary small interfering RNAs or microRNAs, when bound to the 3' untranslated region of a target mRNA, function cooperatively to silence target expression. We report that, in cultured human HeLa cells and mouse embryonic fibroblasts, Argonaute1 (Ago1), Ago3, and Ago4 act cooperatively to silence both perfectly and partially complementary target RNAs bearing multiple small RNA-binding sites. Our data suggest that for Ago1, Ago3, and Ago4, multiple, adjacent small RNA-binding sites facilitate cooperative interactions that stabilize Argonaute binding. In contrast, small RNAs …