PRC2-RNA interactions: Viewpoint from Tom Cech, Chen Davidovich, and Richard Jenner.

Diverse biochemical, structural, and in vivo data support models for the regulation of polycomb repressive complex 2 (PRC2) activity by RNAs, which may contribute to the maintenance of epigenetic states. Here, we summarize this research and also suggest why it can be difficult to capture biologically relevant PRC2-RNA interactions in living cells.

A Large-Scale Sensitivity Analysis on Latent Embeddings and Dimensionality Reductions for Text Spatializations.

The semantic similarity between documents of a text corpus can be visualized using map-like metaphors based on twodimensional scatterplot layouts. These layouts result from a dimensionality reduction on the document-term matrix or a representation within a latent embedding, including topic models. Thereby, the resulting layout depends on the input data and hyperparameters of the dimensionality reduction and is therefore affected by changes in them.

Diverse RNA Structures Induce PRC2 Dimerization and Inhibit Histone Methyltransferase Activity.

Methyltransferase PRC2 (Polycomb Repressive Complex 2) introduces histone H3K27 trimethylation, a repressive chromatin mark, to tune the differential expression of genes. PRC2 is precisely regulated by accessory proteins, histone post-translational modifications and, notably, RNA. Research on PRC2-associated RNA has mostly focused on the tight-binding G-quadruplex (G4) RNAs, which inhibit PRC2 enzymatic activity in vitro and in cells.

Reflections from Nobel laureates in chemistry.

Since the first award in 1901, the Nobel Prize has come to signify the pinnacle of scientific achievement. In this Voices piece in the August special issue of Cell Chemical Biology entitled "Bridging chemistry and biology," we ask Nobel laureates to reflect on the impact the prize had on them. We learn how it affected their life or work, their outlook on science, the lessons learned, and their advice for the next generation of scientists.

Small molecule telomerase inhibitors are also potent inhibitors of telomeric C-strand synthesis.

Telomere replication is essential for continued proliferation of human cells, such as stem cells and cancer cells. Telomerase lengthens the telomeric G-strand, while C-strand replication is accomplished by CST-polymerase α-primase (CST-PP). Replication of both strands is inhibited by formation of G-quadruplex (GQ) structures in the G-rich single-stranded DNA.