Elisabeth M. Mahen

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Multiple studies show that tumor suppressor p53 is a barrier to dedifferentiation; whether this is strictly due to repression of proliferation remains a subject of debate. Here, we show that p53 plays an active role in promoting differentiation of human embryonic stem cells (hESCs) and opposing self-renewal by regulation of specific target genes and(More)
Genetic modification is critically enabling for studies addressing specification and maintenance of cell fate; however, methods for engineering modifications are inefficient. We demonstrate a rapid and efficient recombination system in which an inducible, floxed cre allele replaces itself with an incoming transgene. We target this inducible cassette(More)
RNAs adopt defined structures to perform biological activities, and conformational transitions among alternative structures are critical to virtually all RNA-mediated processes ranging from metabolite-activation of bacterial riboswitches to pre-mRNA splicing and viral replication in eukaryotes. Mechanistic analysis of an RNA folding reaction in a biological(More)
Maternal-effect mutations in NLRP7 cause rare biparentally inherited hydatidiform moles (BiHMs), abnormal pregnancies containing hypertrophic vesicular trophoblast but no embryo. BiHM trophoblasts display abnormal DNA methylation patterns affecting maternally methylated germline differentially methylated regions (gDMRs), suggesting that NLRP7 plays an(More)
RNAs somehow adopt specific functional structures despite the capacity to form alternative nonfunctional structures with similar stabilities. We analyzed RNA assembly during transcription in vitro and in yeast using hairpin ribozyme self-cleavage to assess partitioning between functional ribozyme structures and nonfunctional stem loops. Complementary(More)
The RNA binding protein, DEAD END (DND1), is essential for maintaining viable germ cells in vertebrates. It is also a testicular germ cell tumor susceptibility factor in mice. DND1 has been shown to interact with the 3'-untranslated region (3'-UTR) of mRNAs such as P27 and LATS2. Binding of DND1 to the 3'-UTRs of these transcripts blocks the inhibitory(More)
The tmRNA-SmpB system releases ribosomes stalled on truncated mRNAs and tags the nascent polypeptides to target them for proteolysis. In many species, mutations that disrupt tmRNA activity cause defects in growth or development. In Caulobacter crescentus cells lacking tmRNA activity there is a delay in the initiation of DNA replication, which disrupts the(More)
Accelerating cancer research is expected to require new types of clinical trials. This report describes the Intensive Trial of OMics in Cancer (ITOMIC) and a participant with triple-negative breast cancer metastatic to bone, who had markedly elevated circulating tumor cells (CTCs) that were monitored 48 times over 9 months. A total of 32 researchers from 14(More)
Many RNA-mediated reactions in transcription, translation, RNA processing, and transport require assembly of RNA complexes, yet assembly pathways remain poorly understood. Assembly mechanisms can be difficult to assess in a biological context because many components interact in complex pathways and individual steps are difficult to isolate experimentally.(More)
RNAs must assemble into specific structures in order to carry out their biological functions, but in vitro RNA folding reactions produce multiple misfolded structures that fail to exchange with functional structures on biological time scales. We used carefully designed self-cleaving mRNAs that assemble through well-defined folding pathways to identify(More)
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