The use of small RNAs to program gene regulation and genome defense necessitates ever-changing choices about the sequences used for small-RNA biogenesis. Dumesic et al. now reveal stalled spliceosomes as a trigger for small-RNA biogenesis in the pathogenic fungus Cryptococcus neoformans.

The fungal arginine attenuator peptide (AAP) is encoded by a regulatory upstream open reading frame (uORF). The AAP acts as a nascent peptide within the ribosome tunnel to stall translation in response to arginine (Arg). The effect of AAP and Arg on ribosome peptidyl transferase center (PTC) function was analyzed in Neurospora crassa and wheat germ translation extracts using the transfer of nas...

The mechanism of mitochondrial DNA replication is a subject of intense debate. One model proposes a strand-asynchronous replication in which both strands of the circular genome are replicated semi-independently while the other model proposes both a bidirectional coupled leading- and lagging-strand synthesis mode and a unidirectional mode in which the lagging-strand is initially laid-down as RNA...

Previous evidence indicates that telomeres resemble common fragile sites and present a challenge for DNA replication. The precise impediments to replication fork progression at telomeric TTAGGG repeats are unknown, but are proposed to include G-quadruplexes (G4) on the G-rich strand. Here we examined DNA synthesis and progression by the replicative DNA polymerase δ/proliferating cell nuclear an...

Accurate and complete replication of the genome in every cell division is a prerequisite of genomic stability. Thus, both prokaryotic and eukaryotic replication forks are extremely precise and robust molecular machines that have evolved to be up to the task. However, it has recently become clear that the replication fork is more of a hurdler than a runner: it must overcome various obstacles pre...

bundles undergo deformations highly similar to a twisted rod under compression. Our data suggests that tau-like proteins minimize microtubule lattice interactions and the prevent torque generation that leads to extreme neuron deformations. These experimental results, together with mechanical modeling of the neuron, suggest that spectrin tension and microtubule bundle mechanics are crucial for s...